Longevity of recordable blu-ray discs (BD-R / BD-RE)

▼ So now I got that new optical drive and can start burning CDs, DVDs, BDs (regular 25 and 50 GB blu-ray discs) and BDXLs (newer 100 and 128 GB BDs). But how long will those last?

For each of these types of optical disc, there are three types: mass produced, recordable and rewritable. The mass produced ones are made by stamping physical pits and lands into polycarbonate, cover this with a reflective aluminium layer, and then a lacquer (CD) or polycarbonate (DVD/BD) top layer. DVDs and BDs can have two data layers, BDXLs have three and sometimes four, with semi-transparent reflective layers.

Recordable CDs and DVDs (CD-R, DVD-R and DVD+R) have a layer of photosensitive dye below the reflective layer. The CD/DVD writer uses its laser at higher power to "burn" into the dye layer. With the result that even early CD drives can play CD-Rs without issue. DVD+R improves somewhat on the burn process used by DVD-R.

I'll cover BD-Rs/BDXL-Rs below.

Rewritable or recordable/erasable CDs (CD-RW), DVDs (DVD±RW), BDs (BD-RE) and BDXLs (BDXL-RE) all use a phase change material layer to hold the data. Depending on the intensity of the laser, the phase change material may end up in an amorphous or a crystalline state, which each having a different optical properties.

Longevity: the reflective layer

Obviously all types are sensitive to scratches from poor handling, but the advantage of optical discs over vinyl records and tape is that playing/reading them doesn't involve any contact with the part of the disc that holds the data. So mass produced discs can be played an unlimited number of times without any degradation. For the recordable types, there is a possibility that over time, the reading laser will affect the data layer. But unless you're playing one of these on repeat for months on end, that shouldn't be a problem in practice.

It's widely recommended to store discs in jewel (CD) cases or similar cases where the disc is only held by the hole in the middle, so there is nothing touching it or exerting pressure. And store them vertically.

For mass produced discs, the main issue is that sooner or later, oxygen will reach the aluminium reflective layer, which will then start to corrode and eventually render the disc unreadable. This disc shows lots of small holes in the reflective layer, but so far it plays just fine.

Recordable/rewritable discs often use silver or a silver alloy for their reflective layers. Silver won't corrode immediately just from being exposed to oxygen, but it will in the presence of pollutants like sulfur oxides.

According to Verbatim, a maker of such discs, it's possible to tell the difference between an aluminium and silver blank discs by holding them up to the light and seeing if there's any light coming through the disc. If there is, the reflective layer is silver. If there isn't, it's aluminium.

Of course this doesn't work if there's an opaque layer on top of the disc, for instance, if it's a printable disc. These are pretty nice, by the way:

Longevity: the data layer(s)

The photosensitive organic dye layer in CD-Rs and DVD-Rs is also somewhat of a liability: it will degrade over time. CD-Rs come in various colors that may or may not indicate the type of dye used, with better ones being developed later on.

DVD±Rs always look purple but of course came along when better dyes had been developed, anyway. In practice, I found that out of about a dozen CD-Rs that I burned between 2000 and 2004, one just wouldn't be recognized at all and two others had problems reading a few of their files. For DVD-Rs and DVD+Rs that I burned between about 2003 and 2010, I had issues with about 5% of the discs I tried to read recently.

Rewritables already have the issue that the difference between the two states of the data layer material are much less obvious, but it must also be able to change in two directions, making the addition of room for error much harder. In practice I've had relatively poor results with CD-RWs and DVD-RWs. Sometimes they won't even verify after a burn, and ones from the 2000 - 2010 timeframe had a failure rate of more than 75% when I tried to read them recently.

No problems so far with a box of fresh 25 GB BD-REs, though.

BD-R HTL vs LTH

Which brings us to recordable BDs/BDXLs. Unlike their predecessors, those originally didn't use an organic dye layer to record data, but a composite material, which is more stable. These discs are referred to as high to low (HTL), which gets at the reflexivity of the disc: a blank disc has high reflectivity, which becomes lower when burning.

However, a few years in the disc manufacturers brought the organic dye approach to BD-R, which has the property that the blank disc has low reflectivity, and then gets more reflective after burning, so "low to high" (LTH). This way, the manufacturers could reuse their existing CD-R/DVD+R production lines with only small modifications. HTL discs, on the other hand, require a more complex sputtering production method.

The way I see it, the only reason to still use optical for storage is because of its longevity. The good part is that you can replace a drive and then still read all your existing discs. With hard disk drives and flash, once one part fails (mechanics? electronics? the data?) then you're pretty much left without any useful course of action. In that light, the adoption of LTH BD-R is a step back.

A Reddit contributor felt much the same, but also concluded that LTH BD-Rs had completely replaced HTL BD-Rs in 2018. (Worth reading just for the first comment: "This is one of those posts that shows that it's entirely possible to be 100% correct, and also 100% bat-shit crazy.")

Fortunately, things don't seem to be quite this bad. Yes, it's annoying and perplexing that disc manufacturers don't label their products with important information like whether the discs are HTL or LTH. But, it does seem HTL BD-Rs are still being made, as I ordered a spindle of 10 25 GB Verbatim 6x speed inkjet-printable BD-Rs before I did any research... and it looks like those are HTL. Using Apple's System Profiler, we can see the following under Disc Burning:

We can then look up the ID over at the Disc Manufacturer ID & Media Type ID Licensee List and find out that the CMCMAG BA5 disc type is actually HTL.

Also, if you're careful (it's easy to get confused), you can tell by looking at a burned disc whether it's HTL or LTH. The two discs at the top are a blank DVD+R and a used DVD-R. The ones at the bottom a blank BD-R and a used BD-R.

If you look carefully, you can see that the unused part along the edge on the top right DVD-R is slightly darker than the burned part. For the BD-R at the bottom, it's the other way around, which is easiest to see around the middle. The first ring is very dark, but that one isn't writable. The next ring is writable material, but outside the writable area. This doesn't show up all that well on photos, and it's also easy to misinterpret. But there is a visible difference.

M-DISC

M-DISCs are supposed to last for 1000 years. The accelerated aging tests aren't proving them wrong, but of course also not proving them right. (Wait another 990 years for that.) But at least M-DISCs are making a claim about longevity, which is more than the competition does.

What to do?

If you have data that you want to stay around for a long time, without having to copy it from one HDD or SSD to another every few years, optical is probably the best choice. Still, just writing your data to disc once and then assume it will remain readable for decades is too optimistic. So I'd say:

• If possible, check the error levels for every disc you burn. Unfortunately, this information is generally not available.
• Store everything at least twice, preferably three times. Apply optical disc storage best practices.
• Use different types of discs and/or storage for the different copies.
• Also try to keep the different copies in different locations, both to accommodate for large scale disasters such as fire and floods, but also more mundane stuff such as less than ideal temperature and relative humidity.
• Check your discs once every decade or so, and make fresh copies when in doubt.
• Single layer (25 GB BD) is probably a safe bet, with less to go wrong compared to multiple layers.
• BD-R M-DISC is probably best, with BD-R HTL in second place. Whether BD-RE is better than BD-R LTH is unclear. So when in doubt, use both.

Permalink - posted 2022-01-09

Optical storage and media in the '20s

▼ Last year I wrote posts about listening to the radio, watching TV and having a landline phone in the 2020s (in Dutch). Today, I want to talk about the place left for optical storage in the 2020s.

Do I actually want or need those shiny optical discs in my life?

The short answer: most people probably don't. Software is now always available online, so you don't need an optical drive to install applications or drivers. For music, you can get pretty much everything through streaming services such as Spotify. And if you bought CDs back in the 1990s, you'll certainly have ripped those by now. I think you can watch pretty much any movie on one online service or another. Current TV shows are also generally available on a streaming service.

Transitioning to the disc-free lifestyle

But what if you bought movies and TV shows on DVD in the past, and used to burn some of your data to CDs and/or DVDs? You really want to go over all your data CDs and DVDs and copy those to a harddrive while you still have a working optical drive. That optical drive will die at some point (or become unreliable to the point of being unusable). You can of course then spend less than $/€ 50 for a DVD drive and handle this chore then, but why wait? Those CD-R and DVD±R organic dye layers aren't getting any better as they age.

Ripping movies: meh

I'm not sold on the option to rip all my movies and TV shows on DVD and blu-ray to my NAS or an external HDD. That's just way too much data. For movies, I don't have too much of an issue with simply using my blu-ray player (the one connected to my TV) to watch them. Yes, finding the right disc and then waiting for the drive to do its thing and having to deal with unskippable warnings and annoying menus isn't great, but that's only a minute or so vs a movie that's at least 90 minutes.

Ripping TV shows the hard way

For TV shows, this is quite different. Especially when I want to watch a 22 minute sitcom episode (and boy, do I love those turn-of-the-millennium sitcoms!), having to wait for the player to do its thing and then the warning and menus and me forgetting which episode was next, it's all quite annoying.

So what I used to do before my the Apple USB Superdrive that I got in 2011 kinda-sorta died recently, was rip TV shows from DVD and then use Handbrake to convert them to H.264 format, put in all the iTunes metadata using Subler, and store those on my NAS. However, that is quite a lot of work and eats up quite a bit of storage.

Ripping TV shows the easier way

Then I found an easier way to handle TV shows on DVD (and, to some degree, blu-ray): MakeMKV. MakeMKV is an app that, well, makes MKV files. You can use it to rip DVDs (easy), regular blu-ray (a bit more difficult) and UHD/4K blu-ray (when the stars align). My new blu-ray burner mentioned below didn't give MakeMKV any trouble when ripping DVDs, even region 1 ones on this region 2 drive.

For DVDs with TV shows, it's relatively straightforward to select the right tracks and turn those into .mkv files. However, MakeMKV doesn't do any transcoding. So the video is still MPEG 2, and the audio is still the same (usually) AC3. This means the files will be unplayable in many places, including iTunes and the iPhone/iPad.

However, my LG TV is more than happy to play these files. And, being a TV, it handles the intricacies of framerates and deinterlacing well automatically. fSo I just rip one DVD at a time, put the MKV files on a USB flash drive, and stick that in one of the USB ports of my TV. Yes, the files are three times as large as compared to the handcrafted H.264 versions, but I don't have to think about any settings and just delete the files after watching. Should I want to rewatch the same show a few years from now, I can always rip the same DVDs again.

My new optical drive

Like I said, my Apple USB Superdrive is no longer working properly, and the idea of having a big box full of music CDs and a smaller box full of data CDs and DVDs that I can no longer read bothers me.

So I decided to get a new external USB optical drive. One that can read and write blu-ray discs in addition to CDs and DVDs, of course. I also had a look at UHD blu-ray, which is used for 4K content on blu-ray. However, reading those requires firmware modifications, if possible at all. Dive into the MakeMKV forums to figure that out.

So I ended up ordering a Hitachi-LG BP55EB40 "Slim Portable Blu-ray WRITER" for a little under € 100. Optical drives used to have some issues with the amount of power provided by the USB2 bus in some cases, but that doesn't seem to be a problem anymore. You'd think USB3 would solve that, but no, as the datarates required for 6x speed BD, 4x speed BDXL (100/128 GB blu-ray), 8 x DVD and 24 x CD reading and writing fall well below what USB 2.0 can handle, that's what we get. The drive pretty much handles all the formats:

It will also write M-DISC discs. Those are recordable DVDs or BDs that use a special material for the recordable data layer(s) that should make them last for a thousand years.

Blu-ray for archiving

I'm not sure if my data still needs to be available in the year 3022, and it probably won't be, even on an M-DISC, but given that my failure rate from the DVD-Rs that I burned between about 2003 and 2013 is quite low (maybe 1 in 25 is no longer readable), an improved type of recordable disc seems like a good bet for things that need to last a few decades.

The advantage of an optical disc as an archival medium is that it only includes the data, not any electronics or logic. It's also fairly small and especially flat, so you can mail them or store them in a folder or safe deposit box and not worry about shocks or drops. A couple of years ago, I wrote about using flash for archiving, purely based on price. However, as flash capacities have gotten larger, especially for USB thumb drives and SD cards, their reliability has dropped. This is not a technology appropriate for long time archival storage.

Also, unlike storing data on a (possibly archival) hard disk drive (HDD), burning a disc is a one-time thing, so it encourages careful consideration of what needs to be archived in what format.

Conclusions

Although I think it's possible to leave the optical past behind, I do think keeping an optical drive around to rip TV shows and burn archival copies of my data is a good idea.

Permalink - posted 2022-01-02

Mixing old and new Nikon lenses and cameras

▼ Seven years ago, I wrote Understanding old Nikon lenses: AI, AI-S, AF and AF-S. A few things have changed since then, so I thought it was time to do a follow-up that looks at how well different Nikon lens generations go with different Nikon camera generations.

The easy solution is of course to uses lenses and cameras of the same generation. All Nikon cameras introduced since about 2015 work with all Nikon lenses introduced since about 2000. But where's the fun in that?

First: what’s new since my previous article: AF-P lenses, E lenses and the new Z mount.

AF-P

For the past 20 years or so, Nikon’s autofocus lenses used ultrasonic "silent wave" motors in their AF-S lenses. AF-P lenses use pulse / stepper motors. Those can make small changes very quietly, so they're great for video. A big difference between AF-S and AF-P lenses is that the manual focus ring on AF-P lenses is not mechanically connected to the lens elements. Instead, the focus ring sends information back to the camera, which then uses the focus motor to change the focus.

This change means that the camera needs to know about AF-P lenses, or you won't be able to focus. Cameras introduced starting around 2013 support AF-P lenses. For some of these, a firmware update is required, and possibly there will be some reduced functionality.

E (electronic aperture) lenses

AF-P lenses also tend to be type E, indicating the lens has an electromagnetic aperture diaphragm actuator. (Not to be confused with "E series" manual focus lenses.) Support for E lenses goes back a few years further than AF-P lenses, to around 2008-2010, depending on the camera type.

Z mount

In 2018, Nikon introduced the Z line of mirrorless interchangeable lens cameras, and these cameras no longer have the F mount that Nikon's SLRs have used since 1959. Nikon has released a number of Z mount lenses, which are all AF-P as well as type E lenses. Of course these lenses don't work on older cameras, but F mount lenses will work on Z series cameras through the FTZ adapter. All the discussion below is about F mount lenses, for Z type cameras use of the FTZ is assumed.

The lens types

From left to right: pre-AI, AF-S type G, AI, AF type D, AI-s

So now we have an understanding of the following types of lenses:

• Pre-AI: manual focus
• AI or AI-s: manual focus
• AF: focus motor in the camera body
• AF-S, DX and FX, ultrasonic focus motor in the lens
• AF-P, DX and FX, stepper focus motor in the lens

All types of AF lenses also have a CPU in them which lets the lens tell the camera its properties. Let's see how they work on different cameras. I'll talk about the following specific cameras that I own, or more broad categories:

• Nikon FE, standing in for the AI type manual focus film cameras (around 1980)
• Nikon F65, as an example of a late lower end autofocus film cameras (around 2000)
• DX, the lower end crop sensor DSLRs (D3x00 + D5x00 and their predecessors)
• D7x00 and their predecessors mid-range DX camera with AI/AF lens support
• FX, the full frame high(er) end cameras
• Z DX: the Z50 and Z fc
• Z FX: the Z5, Z6 and Z7

So here we go.

Nikon FE and contemporaries

• Pre-AI: camera doesn't know aperture setting, so problematic metering
• AI or AI-s: perfect!
• AF: good!
• AF-S type G: no aperture ring, so fixed aperture and problematic metering
• AF-P: focussing impossible

Nikon F65 and similar

• Pre-AI: mounting will cause damage
• AI or AI-s: no CPU, so no or problematic metering (manual focus)
• "AF": perfect!
• AF-S, FX: perfect!
• AF-S, DX: typically black corners, some lenses may work to some degree
• AF-P: focussing impossible

DX DSLRs (lower/mid-range)

• Pre-AI, AI, AI-s: no CPU, no metering
• AF: manual focus
• AF-S: perfect!
• AF-P: depends on camera age

D7x00 and its predecessors

• Pre-AI: mounting will cause damage
• AI, AI-s: no CPU, enter lens data manually (manual focus) (no metering on D7500)
• AF-D: perfect!
• AF-S: perfect!
• AF-P: depends on camera age

FX DSLRs

• Pre-AI: mounting will cause damage
• AI, AI-s: no CPU, enter lens data manually (manual focus)
• AF-D: perfect!
• AF-S, FX: perfect!
• AF-S, DX: automatic cropping, but viewfinder shows black corners, some lenses may work in FX mode to some degree
• AF-P: depends on camera age

Z mount DX with FTZ

• Pre-AI, AI, AI-s: no CPU, so stop down metering, reduced focus aids
• AF: manual focus, reduced focus aids
• "AF-D": manual focus
• AF-S: good, somewhat hunting and noisy focus in video mode
• AF-P: perfect!

Z mount FX with FTZ

• Pre-AI, AI, AI-s: no CPU, so stop down metering, reduced focus aids
• AF: manual focus, reduced focus aids
• "AF-D": manual focus
• AF-S FX: good, somewhat hunting and noisy focus in video mode
• AF-S, DX: automatic cropping, also the viewfinder image, somewhat hunting and noisy focus in video mode
• AF-P FX: perfect!
• AF-P DX: automatic cropping, also the viewfinder image

As always, additional caveats may apply, be sure to check compatibility for your specific camera before you go out and get new lenses.

Conclusions

It looks like the D7100/D7200 as well as the not-too-old FX cameras are compatible with all F mount lenses. There is not a single lens type that works fully with the entire range of cameras, but the AF type D lenses come closest: they work on the old manual focus cameras, work with with autofocus on the mid/higher end DSLRs and still work fully as manual focus lenses on all other cameras.

An AF type D lens is still largely usable on cameras like the Z family, where you'll have to focus manually. But with the traditional "electronic rangefinder" focus aid available, where the autofocus system tells you if you've achieved focus, that's actually a bit easier than on an old manual focus camera such as the FE. However, manual focus lenses without a CPU for some reason don't get full focus aids on the Z cameras. You can still focus very precisely by zooming the viewfinder, but this is quite slow.

So there you have it. I'm sure the next few years the second hand F mount lens market is going to quite interesting, as more and more Nikon users migrate to a Z camera or a non-Nikon mirrorless camera.

Update:

In the original version of this article, I mistakenly said AF lenses that are not AF-D lenses don't have a CPU. That's incorrect. On DSLRs AF and AF-D lenses work the same, but for some reason on a Z camera (through the FTZ) the AF-D lenses have full focus aids but AF lenses have reduced focus aids. However, AF lenses are still more functional than non-CPU manual focus lenses because on AF lenses, the camera can control the aperture.

On non-CPU lenses, the camera doesn't know the aperture so it's difficult to use apertures smaller than about f/5.6 or f/8 because focussing gets more difficult at smaller apertures, so you may have to use stop down metering.

Permalink - posted 2021-10-09

Amiga short takes, juggling CF cards edition

▼ In this latest installment of Amiga short takes:

• Iconverter v1.0 released
• Just use FAT32 for your external CF cards
• Back up to HDF images
• CardBootDisk
• Joystick restrictor plates
• The Deathbed Vigil
• WHDLoad doesn't like network connectivity

Iconverter v1.0 released

Almost two months ago I released version 0.8 of Iconverter, a tool to convert old Amiga icons so they look right on Amigas running a newer OS version. Version 1.0 will now write ColorIcons by default, but can still write NewIcons. It can also read NewIcons and ColorIcons, and thus covert between the two. And write BMP files. (See the Changes section in the documentation for more details.) Available here and on Aminet.

Amiga 3000 boots a lot better with FastFileSystem added to a boot partition

Because I was getting read errors on the CF card that my Amiga 1200 uses as its harddrive, I decided to play musical chairs with all the SD cards. Which resulted in my 3000 not willing to boot even though it had three perfectly good boot partitions on different drives available. (The superkickstart that needs to be loaded from the harddrive makes the 3000's boot process rather complex.)

These issues went away after I used HDToolBox to "add" the 3.0 version of the FastFileSystem to these boot partitions.

Just use FAT32 for your external CF cards

Replacing the CF card is the easy part. The hard part is getting all the data from the old one to the new one. Now I could slightly cheat because I have an IDE-to-CF adapter than can take two CF cards. With that, it's just a question of setting up the right partitions and copying all the data with copy DX0:#? to DY0: all clone.

In the past, I've managed to mount Amiga-formatted CF cards using a PCMCIA adapter. But that's quite a bit of work and often unsuccessful. However, mounting FAT32 formatted cards in the PCMCIA slot is super easy. So after inserting a third, FAT32-formatted card to temporarily hold the data in the PCMCIA slot, now it's time to...

Back up to HDF images

Obviously it's possible to copy all the files to the FAT32-formatted card. And even though the Amiga isn't too picky about special file properties, there's always a chance that something gets lost in translation. Also, copying individual files is relatively slow. It's much faster to just write an HDF image of the partitions on the old card to the temporary card. The TSgui tool will do that.

This worked very well on my Amiga 3000, but not so much on the 1200: systems running Workbench 3.0 said the image "was not a DOS disk". After I got 3.1.4 back up and running again on the 1200, it mounted the images just fine. However, I couldn't make an HDF image of my largest partition at all. It looks like TSgui is limited by the original Amiga 4 GB drive size limit.

Still, it's not a bad idea to create empty HDF images (or download these) and mount those with ImageMount and copy files to the image rather than directly to the FAT-formatted card. Just make sure to check whether they're readable before switching those internal CF cards...

CardBootDisk

So now you have an empty CF card inside the Amiga and a FAT-formatted card with all your data (and, for good measure, ADF files of the Workbench disks and a copy of HDToolBox). Then you turn on the computer and it doesn't see any of that. So I made a CardBootDisk, which is a floppy that has all the drivers to mount FAT-formatted cards in the PCMCIA slot and ImageMounter to mount ADF, ISO and HDF images. So after booting from that floppy you can partition your new internal CF card and start copying data to it. If you forgot anything, just plug the CF card into another machine (in my case my Mac) and copy the missing data on the card and put it back in the 1200.

Download the ADF image of the CardBootDisk. Tip: if you're installing a fresh copy of AmigaOS, first copy all the files from the CardBootDisk to the harddrive and then install the OS over it. You should then still see the CF card after booting from the harddrive.

Joystick restrictor plates

I got an arcade style joystick recently. I'm not entirely happy with it, but I also don't want to write a bad review. So I'm just not going to name any names. Anyway, the actual joystick mechanism is great, much better than my old joysticks from the C64 days or the ones that come with THEC64. (Too bad the THEC64 won't recognize this joystick when used with a perfectly good DB9-to-USB adapter.)

The thing I wanted to mention is the restrictor plate. This one came with a square one with rounded corners. When playing my favorite game, BoulderDäsh, that doesn't work very well. When for instance you move right, but not exactly at a 90 degree angle, but let's say 95 degrees, the restrictor plate makes it really easy to slip down to 120 degrees or so and now you're trying to walk diagonally. Which makes Rockford walk down.

The fix is to rotate the restrictor plate 45 degrees. Now the round parts catch the underside of the joystick as you move left/right/up/down. But in this configuration, it's almost impossible to move diagonally. So for games that need that, this is unworkable. Solution: get a new restrictor plate. Gaming supply shops sell those. I got an octagonal one, which works fine, but perhaps a round one would have been even better.

Restrictor plates. Who knew. Of course with arcade games a joystick would only be used with a single game, so it makes sense that there are different ones that allow for different degrees of freedom. Something to check for when buying joysticks.

The Deathbed Vigil

Recently I rewatched "The Deathbed Vigil and other tales of digital angst", the movie Dave Haynie made of the last days of Commodore. If, unlike me, you didn't get your VHS copy 25 years ago and still have a VCR to play it, you can now also watch the movie on Youtube. Don't miss the "Chicken Lips Blues" at the 55:30 mark.

WHDLoad doesn't like network connectivity

A good way to easily run demos and games, especially floppy-based ones, is with WHDLoad. On the official website they focus on providing "slave" definitions that allow you to import your existing copy of games, but of course helpful individuals around the internet have already imported lots of games... You then just click an icon and you can start the game.

However, when I tried installing WHDLoad last year, I could only get a handful of games to work, most would just show garbage on the screen. But then when I was messing about with CF cards, all of a sudden all the games worked. Turns out that WHDLoad makes some kind of network connection (as it tells me there is a newer version) and then doesn't work properly. Shutting down the network before starting any games fixes that.

Update:

I blocked cgi.whdload.net so WHDLoad can't perform its update check, but that didn't help. After some further checking, it looks like it's a hardware issue with the way PCMCIA network cards work. I normally use the I-Card, which is a wired 10 Mbps Ethernet card. With that one, if I shut down Roadshow, my networking software, WHDLoad games work. Or, keep the network stack running but unplug the Ethernet cable. But as soon as I plugged the cable back in and the Amiga started to receive (broadcast) packets, the game stopped working. So I'm guessing the issue is with interrupts generated when packets arrive.

With the 11 Mbps Wi-Fi card there's obviously no cable to disconnect, and just shutting down the network stack isn't enough: the Prism driver comes with a WirelessManager program that handles connecting to the right network, so you need to shut that down, too. Use the status command to see the process number (for instance, 6) and then type break 6. Interestingly, taking the wireless network down by turning off the wireless access point also works, even though the activity light on the Wi-Fi card still blinks once in a while.

And... then it turns out this is a known bug. RTFM, Read Those Fine Manuals. Weird though that WHDLoad happily uses the network as you start a game and doesn't issue a warning.

Permalink - posted 2021-08-15

(Re)creating new Amigas for the 2020s and beyond

▼ Two forum posts made me think of what it would take to build an Amiga using modern parts, and what should remain the same and what should change about a new Amiga to remain useful in the next decades.

The first is on AmigaLove, a forum that I found recently and that I enjoy participating on: FPGA Custom Chips. The original post is about creating FPGA implementations of the Amiga's custom chips. That way, it's possible to replace the original chips when they fail, or build a new Amiga from scratch.

The other one is on the MiSTer FPGA Forum: Faster CPU for Minimig core?. (Minimig core = Amiga on the MiSTer.)

(An FPGA is a field programmable gate array, or basically a lot of small parts that perform functions used in all kinds of computer chips, and these parts can be connected in different ways so the FPGA can "become" lots of different chips.)

But what should be our goal?

Obviously, some of us, especially those who still have Amigas that we use from time to time, would love to retain access to something as close to an original Amiga as possible. However, then what about the peripherals?

Today, if you bring an Amiga into a home, there's a 99% change that you can't hook it up to a TV or monitor there, and a 99.9% chance you can't exchange any files between the new Amiga and anything else.

So I say: a new Amiga needs to be more like a THEC64 than an actual Commodore 64 (well, actual Amiga). That means: HDMI for video output and the ability to use USB peripherals.

And that's not impossible. I'm typing this on my Amiga 1200 right now, but I'm using an HDMI monitor thanks to the Indivision AGA MK3 adapter and a USB mouse thanks to the MouSTer adapter. And a USB keyboard thanks to the Rapid Road USB adapter, but I readily admit that that's just showing off. (Although the CTRL keyboard types a lot nicer than a 28-year-old Amiga 1200 keyboard.)

What this could look like is just like with the original Amiga generations, two versions: one integrated with the keyboard, and a "big box" model. I think for the integrated one, a case that holds the middle ground between the A600 and A1200 would make sense. Remove the numeric keypad but keep the cursor keys. This is something new, it doesn't have to look exactly like its predecessors. For the big box version I think something that looks like an A3000 but smaller would be great, or maybe even a smaller version of the Amiga 1000 case.

Chipset and floppies

Obviously to run old games, the chipset needs to recreate the A500/A1000/A2000 chips exactly, as seen by Amiga software. So USB peripherals such as mice, joysticks and keyboards must be remapped to recreated versions of the Amiga hardware. I think that also needs to apply to the floppy drive, as so many games and demos had their own floppy drive code. Perhaps the machines should optionally have an actual floppy drive. That way, access to the floppy-based Amiga legacy is guaranteed. But most of the time, an integrated Gotek-like floppy emulator would do the trick.

(And the middle ground: something that physically looks like a floppy drive and accepts floppies and floppy-shaped objects, but then only reads a barcode from the back to mount the right disk image. That would provide the authentic experience without all the issues with actual magnetic storage.)

Ports

On the one hand, it would be great to have all the original ports, but on the other hand, that is more difficult/expensive, for probably relatively little benefit. Let's have a look:

Mouse and joystick ports: it's easy to map USB mice/joysticks to the Amiga hardware. I'm doing that right now. Then again, the hardware is super simple, so perhaps the ability to use the real thing isn't too onerous.

Video: I'd say: just embrace HDMI and leave the past behind. Of course add good scaling and filters and especially handle PAL vs NTSC well. One of the cool things only the Amiga could do is switch video modes on the fly when cycling through screens.

Then again, the MiSTer FPGA platform does support analog video out currently. Could this be an option? But a complete Amiga video connector, genlock-capable and all? Too much to ask, in my opionion. If you really want that, use an original Amiga in good condition.

Audio: one of my complaints about the modern THEC64 is that it only outputs audio over HDMI. That's pretty limiting. Please give us line out for those sweet, sweet MOD files.

External floppy: not sure how difficult this is. But is it useful? For an internal floppy option, a PC floppy drive can be used (the differences are extremely minor and can be accommodated in a recreated chipset), but external Amiga floppy drives are more complex. And one physical floppy drive along with additional emulated ones seems more than adequate.

Serial: there are a few uses for the serial port that are still relevant, I'd say. So having the Amiga think it has a working serial port would be useful, but not sure if having the additional hardware is very necessary. The Amiga's serial port could be mapped to a USB serial port but also be mapped to a network service.

Parallel: well, parallel printers are dead. Not sure if there's any printers left with reasonable Amiga drivers. Intercepting the Amiga's print output and saving it to a file for later display, conversion and then printing to a modern printer makes more sense. But the parallel port was also used for all kinds of interesting stuff, such as the Digiview video digitizer. Not a priority, but on the other hand: just a bunch of GPIO (general purpose IO) pins seems workable.

A1200 hardware

So that's all the ports you'll find on an A500 / A1000 / A2000. But there is more. Next to the A500, the A1200 is the big gaming platform that you'll want to support to let people play AGA games. So:

Harddrive: lots of Amiga software needs a harddrive. And again, I think the right approach is to recreate something that looks like the original Amiga hardware from the software side, but then remaps to modern hardware. I'm thinking an SD card as the harddrive.

PCMCIA slot: used for all kinds of stuff, but mostly to exchange data with other systems on CF cards and for network cards. I would replace this with an (additional) SD card slot. As using CF cards in this slot required extra software anyway, it would be fine to have an extra AmigaOS driver to talk to this SD card slot.

68020: the A1200 uses the 68(EC)020 CPU. So in order to run software made for the A1200, it's necessary to support the 68020.

More advanced hardware

Retargetable graphics (RTG): most non-game software on later AmigaOS versions will happily run on screens powered by RTG graphics cards. These don't have the limitations of the Amiga's chipset. So RTG support that integrates well with the Amiga's native graphics capability would be extremely useful.

68030: the Amiga 3000 uses the Motorola 68030 CPU. The 68030 isn't very different from the 68020, except that is has an MMU. Not a feature that is used a lot by Amiga software, but still useful in some cases. So not a top priority, but nice to have. 68040 and 68060 were a lot faster, but also less compatible. It's probably more useful to make the 68020/68030 implementation faster than to recreate the 68040 or 68060.

FPU: the Amiga 3000 has a 68882 floating point unit, and Amiga 4000s with a 68040 CPU had a built-in FPU. I think in general Amiga software doesn't require an FPU, but there could be situations where not having an FPU creates issues, such as having to use a less capable version of some software.

And an FPU speeds up some software quite a lot. (I think some people doing MiSTer Minimig benchmarks aren't comparing their results to FPU-enabled results.)

Perhaps giving up some accuracy for speed makes sense here, for instance by emulating the FPU (or CPU+FPU) in software rather than use a cycle exact FPGA implementation to run this kind of software.

Last but not least: networking. No original Amiga came with a network card. So recreating old networking hardware doesn't make much sense. However, some way to implement networking functionality does. Not sure if a bsdsocket.library that simply punts network calls to the ARM CPU that runs a Linux variant makes sense, or perhaps something that looks to the Amiga like Ethernet hardware and is then bridged with Wi-Fi. That way, the Amiga can use "real" networking but doesn't have to keep up with changing Wi-Fi (security) standards.

Well, that's my vision of future Amigas. Now the only thing to figure out is what model number they should get. 1600? 5000?

Permalink - posted 2021-08-08

Review: MouSTer: making my favorite wireless mouse work with my Amiga

▼ Original Amiga mice were never that great, and a few decades of use and storage didn't help. So if there's one part of the Amiga I have no problem replacing with something new, it's the mouse. (Don't feel bad, I swore of Apple mice, too.) So a while ago I got a USB-to-DB9 mouse adapter. That one worked fine with wired mice, which was a big improvement.

An Amiga 3000 "tank mouse", an Amiga 1200 mouse and a 2000-era Logitech Mini Wheel Mouse

However, a few years ago I discovered the Logitech Anywhere MX 2 wireless mouse. I liked it so much I got one for at home and one for at work. The MX 2 is a bluetooth mouse that can pair with three computers. You can simply switch to another computer with a small button at the bottom. Now obviously the Amiga doesn't do bluetooth, but the MX 2 comes with a Logitech unifying receiver, which you can plug in any USB port and then the computer thinks it's talking to a wired USB mouse.

Problem solved, right? Not really. The MX 2 didn't work with that adapter, nor with another one. Eventually I went as far as to get a RapidRoad USB adapter for my Amiga 1200. This does work very well most of the time, but the complex USB software is not compatible with most games and is not 100% reliable.

The MouSTer connected to a DB9 extension cable, with the Logitech unifying receiver and the MX Anywhere 2

So when I read about the MouSTer, I thought four times might be a charm. After waiting for the little device to make its way from Poland to Holland over the course of very many days, it arrived today. So I plugged it in and... not much. The mouse pointer did move a pixel or two, but nothing close to working correctly. Then I noticed:

So I plugged a USB thumb drive into the MouSTer, which produced furiously blinking LEDs. Afterwards, there was a new directory on the flash drive, with in it a file named MOUSTER.INI. This is a text file with settings and clear explanations what they do. Out of the box, the MouSTer was set up for the Atari ST (hm, maybe the capitalized ST in the name should have been a clue?). I quickly changed that to "amiga". For good measure, I downloaded the latest firmware and put that next to the MOUSTER.INI file and put the thumb drive back into the MouSTer. After that, different mice worked as expected, with just some tweaks to the DPI divider and LED heartbeat settings needed.

A modern optical mouse like the MX Anywhere 2 sends way more "hey, the mouse has moved" pulses than the Amiga expects. As a result, when you move the mouse quickly, the mouse pointer jumps around because the computer can't keep up. Using a DPI divider ("microstep") value of 2 - 5 on the MouSTer didn't completely solve that for me, but using the Mac Logitech Options program to tell the mouse to use the minimum pointer speed, along with a microstep value of 2 made everything work satisfactorily.

Amiga mice normally have two buttons. The DB9 port has just one unused wire, so the Amiga can recognize a third button, but that's it. No scroll wheels—without using different hardware. However, the MouSTer will helpfully map any additional mouse buttons to the three the Amiga can recognize, with or without autofire. A program like FreeWheel will let you do something useful with the extra mouse button.

You can tell the MouSTer is starting up after turning on the computer because its yellow-orange light flashes furiously. (It'll tell you any error messages in morse code.) This is fast enough that if you press both mouse buttons as you turn on the computer, you're greeted by the boot menu as intended.

Conclusions: after only a few hours of use, I'm already a fan of the MouSTer. The hardware is nice and small, so it doesn't stick out far enough to get in the way. The electronics are visible, but covered with plastic so no chance of accidental shorts. The configuration method is unorthodox, but works well. I tested it with both a wired and a wireless mouse, as well as a couple of joysticks. Everything worked. (It also supports gamepads.) Using the Amiga mouse port is a mixed blessing. On the one hand, it's a limitation: only the one extra middle button and no scroll wheel support. On the other hand, it works with everything. In my case, I simply use two Logitech receivers: one on the MouSTer and one on the RapidRoad. So I just flip the mouse and push a button to switch between features and compatibility. 😎

Permalink - posted 2021-07-24