A thought about the P2, its current status and its future.

  • Greetings,

    About five years ago, I bought my Spanish P2, at first I thought it was some sort of S-100 system, but I could never imagine that for this amount of time I'd have the only known unit of a regional variant. About two weeks ago, a second unit was found and while I have some relief, the fact that it's not working doesn't help. For about these five years, I have barely turned it on, as its PSU was half-dead and the truth is that I don't like much the ATX patch (for a temporary solution is ok, but for a permanent one...).

    In November, I decided to start drawing my memory board and in early December, when my Italian unit arrived half-working I found too many single points of failure (SPF from now) that may prevent a unit to work. There are other related issues that does not prevent them to work but should also be addressed.

    * The power supplies are slowly dying.

    * Case cracks and disintegrates.

    * All ROMs are non-standard TMS-27xx.

    * The use of specific, specialized components (such as the VTAC) and cost of future replacements.

    * Broken keyboards with missing parts.

    And a few more.

    These issues are so common between current owners of this system that individualized solutions are not effective anymore. As every unit will eventually die for the same causes I think we should set some sort of standard. I've started talks with a relative of mine, who is more qualified than me in analog electronics, to start working on a new PSU. I don't know if we'll reach anything, but it's worth trying.

    There are also issues with information regarding the computer, from its ROMs' images to manuals. If my Spanish character ROM dies now, no replacement is available, I'd have to pray that overCLK's (the only other Spanish user) is working and wait him to dump it. Most other regional versions are unaccounted. Lost?

    My question is if anybody has some sort of idea to maintain the systems running for a few more years. I'd be glad to hear your opinions.

    Thank you very much!

    When I tried to list all retro systems I have at home, the "The message is too long, must be under 500 characters" error appears! :lol:

  • jlopez

    Changed the title of the thread from “A reflexion about the P2, its current status and its future.” to “A thought about the P2, its current status and its future.”.
  • Interesting thoughts.

    I guess the situation will become more or less the same for other computer systems. It's even worse for those that are not easy to find, or used not the most common hardware solutions.

    The problem is that as time goes by, replacements will be more and more difficult to find. Nowadays it's easy to find for instance, any DIP packaged 74LS chip, or the most common processors/controllers of the 80's. But I fear that it will become more and more difficult in the future.

    So maybe in some years, we will have to rely to emulation (software or CPLD/FPGA) to keep the computer running. I consider that emulating by hardware a whole system like the Alphatronic P2, specially with the documentation currently available, is a huge task, but maybe the future only option. There are, of course, lots of possibilities:

    - Keep the main chips (controllers, , emulate the additional logic with CPLDs) and provide replacements based on CPLD + main chips for the different cards

    - Just emulate the whole system on a single chip (FPGA), but providing connectors for the representative parts (floppy, composite video,...) or even provide a backplane replacement enabling old working cards to be connected (disabling emulation for those parts).

    Regarding the case, I suppose that nowadays plastic injection molding is the only technique providing a decent result. I made 3D printed replacements for some computers (half a case for an Atari ST somebody cut away), or cases for different peripherals,.. but of course it's not the best solution (it's a home printer anyway, maybe the professional ones provide better results). Plastic injection seems to be also very expensive unless you have a good amount of requests. The Alphatronic P2 has additionally a huge case. :)

    But at least for me the question is, at what extent a computer is still the same computer if we replace its components. :)

    I'm OK with changing the power supply, or replacing a floppy drive with a more practical emulated solution(flashfloppy, Hxc). But replacing the brain of the computer with something emulated… that is another story. Of course if there is no other option, I would be ok with a new brain as far as I could keep the case and the keyboard as it is. I would also replace the CRT with a LCD solution, keeping the same case.

    For me, the retro computing is a lot about the feeling. I don't feel the same touching my very first Amstrad CPC6128, or typing on my Northstar Advantage (the first one I used at school) than on some software-emulator. It's about the noise they make when you turn them on, the feeling of the keys, the ritual of inserting a disk in the drive, typing a command, and hear the disk spin and the head moving (even how the CRT smells when it gets warm),... Feelings that bring me back to that age. Yes, sorry, I'm getting old. :)

    But of course, nothing lasts forever (and neither do we). And being able to keep the original ROM contents and emulate all the peripherals would be enough to at least keep some distant echo of how the thing looked like and worked. Let's say we will have a photo of the real thing, but not the real thing.

    Just my two cents. ;)

  • Thank you for answering!

    The fate for most computers of that era is already sealed. With custom chipsets they will not last long. Other systems will last for a very long time, such as the Commodore PET (pre-CRTC), Apple II or the ZX-80, which are made of generic, off-the-shelf materials which, in case of the most specific ICs can be replaced with small mods. However, we have a case of a computer which has avoided its demise by getting rid of its ASIC. The ZX Spectrum case should be studied. They replaced the ageing ULA with (mostly) 74 series ICs. This means that, as long as the 74 series (with TTL levels), the Z80, its ROM and its RAM are made, Spectrums will be able to be made and repaired (although those with original board will eventually fail nevertheless).

    I think if the Harlequin philosophy could be applied to this system, we would be able to keep them running for some more time (and also to introduce new units). The truth is that I'm not a fan of FPGA or CPLD. They obscure hardware implementation and make it less repairable in case of failure. Also, they doesn't feel retro enough. ;)


    When I tried to list all retro systems I have at home, the "The message is too long, must be under 500 characters" error appears! :lol:

  • You're welcome. This is in fact an interesting discussion.

    At the end, custom chipsets were there to save costs and power consumption. We can either emulate the bare 74LS logic or the custom chipsets with CPLD/FPGA solutions. Do I like it? Well, it's a solution. What I don't like is hearing that this is the real thing, like I have heard lots of times. It's just emulation at a different layer, is'nt it? ;)

    I have one of my Spectrum ZX running on a Nebula replacement and it's somehow a satisfactory approach. It would be better to have the real thing, but… from an user perspective you cannot tell the difference unless we are talking about some artifacts of the original device. But for 99,9% of the requirements, it is OK.

    And at the end, at least in my case, I do this just for fun. And trying to implement a system or part of it on CPLD/FPGA logic can also account for fun. And it forces us to understand all the low level details of the target system.

    What I'm not for is a methacrylate box emulating everything on a chip, with HDMI output and not even the original I/O ports. But of course I understand they also have their addepts, and I'm not against it. But I think the original spirit is somehow lost. :)

    Anyway, let's see what the future brings. But what today is stock material, maybe it's not anymore in some years.