Hi Mike!!     Oh I was so nervous taking it apart - I was thinking of you,
and worrying about how I'm probably going to end up having to sadly explain
why this system doesn't work anymore.  But 'lo and behold, I did manage to
get it back together!  (notes are in my PC-5000 page linked earlier, which
is now a bit long winded for a single page - I'll spit it out eventually).


I was trying to go after the CMOS battery, or its equivalent - but wow,
Sharp made that very difficult.   As you'll see in the photos, the
component side of the mainboard is actually pointed down.   Since this is
still very much a working system, I didn't feel comfortable completely
disassembling it - you have to get the entire mainboard out.  But I got to
the vicinity of the area at least.  On the positive, my thinking is that
since the battery is "inverted" from normal and pointing towards the ground
- if it does leak, it'll just leak into the plastic base of the system.

With the disk drives, I can now get new software onto the system more
easily.  But, looks like I'll have to give up on making a boot disk floppy
for the system.  I've added a ton of notes to my PC-5000 page about it.


@Fred Cisin -  I did manage to digest and follow your DEBUG.COM advise, and
it all did work (in getting past "incorrect DOS version").  But when it
came to the business of actually executing a format, they still did not
work.  As others have suspect, we're just going to need to find that
original Sharp MS-DOS 2.00 boot disk someday.   In poking around the MS-DOS
2.00 source code on github, it actually doesn't have a pre-built FORMAT.COM
- instead it has a FORMAT.DOC file that describes notes on what is expected
for an OEM vendor to implement to support doing a format.    While we did
finally find a format that allows SYS.COM to work, it's still mysterious on
why the (bootable) bubble memory report 6 hidden files, but a SYS'd disk is
only reporting 2 hidden files (I think someone else here did cover that, in
suggesting some vendors did need extra files to fully implementation their
DOS?)   So it's been a valiant effort, but I'm content enough just being
able to move files on/off the system via disks - meanwhile we'll just hunt
for that original Sharp MS-DOS 2.00 image, it surely is somewhere "out
there" eventually.
(again, notes on this are on my PC-5000 page - but the short of it is:
- MS-DOS 1.25 FORMAT.COM didn't care about version but didn't even try to
actually format (locked up)
- (Sharp) MS-DOS 2.11 FORMAT.COM was patched, and would show help on
command line arguments, but wouldn't actually run when given /2 /8 or /S,
etc.
- MS-DOS 3.30 FORMAT.COM was patched, but declared the target drive as
ASSIGNed or SUBSTed and refused to proceed


The disk controller interface on this system just isn't "PC Compatible"
enough.

-SL






On Sat, Oct 19, 2024 at 12:43 PM Mike Stein <[email protected]> wrote:

> Great to see my old PC5000 receiving so much loving attention; thanks
> Steve!
>
> FWIW, related to the discussion elsewhere about BBSs, that PC5000 was
> originally owned by Canada Remote Systems, a smaller Canadian version of
> Compuserve based here in Toronto, It was a fairly large (by Canadian
> standards) commercial BBS system of the 80s and 90s, noted primarily for
> its extensive file collection; I think I still have some of their
> collection disks on 8" media somewhere.
>
> On Sat, Oct 19, 2024 at 10:05 AM Steve Lewis via cctalk <
> [email protected]> wrote:
>
>> Some interesting things (on PC-5000):
>>
>> - I copied over QMATH, and old command line "parsing-calculator" I did in
>> Turbo Pascal decades ago (probably about 1992, so post MSDOS5 at least),
>> and it runs on the PC-5000!  It's packaged in my "VUC" tools here  (along
>> with CDIR)  voidstar78/VUC4DOS: voidstar Utility Collection for (MS/DR/PC)
>> DOS (github.com) <https://github.com/voidstar78/VUC4DOS>
>> That just speaks well to the PC-5000 really being MS-DOS compatible (and
>> that it ran an executable from a much later generation of MS-DOS).   Note
>> that CDIR itself doesn't run on that MS-DOS 2.00 system (I suspect
>> anything
>> that "touches color" won't run, based on trying to run a few other similar
>> type things)
>>
>> - VER is saying MS-DOS 2.00, same as the startup/bootup note.  Though it
>> does say the "Command v2.02" shortly after (I suspect as it is loading the
>> command.com, or in any case just prior to invoking autoexec.bat)
>>
>> - I don't have a "native" DEBUG.COM for 2.X yet (and ended up in a bad
>> time
>> that archive.org is majorly down again).  And trying to run DEBUG.COM
>> from
>> 3.30 disks on the PC-5000 just says "Incorrect DOS version" (was we've
>> discussed, which as mentioned I'll have to debug the debug.com on another
>> system first to patch it)
>>
>> I'll dig into the .COM patching later, have some errands this weekend
>> first.  Plus, it turns out I "blew up" my parallel port *again*.   Modern
>> day, we take it for granted about USB being hot-swappable.  Well,
>> parallel-ports apparently aren't that forgiving - and I keep forgetting
>> that.  I've zapped two parallel cards now while swapping between parallel
>> devices.   (which I'm making good progress figuring out the "retro
>> printer"
>> that will emulator old printers and let us print from old software and go
>> straight to a PDF, but still working on it)   The LPT devices themselves
>> are fine, just I really heard the electrical pop and just the parallel
>> port
>> is absolutely dead (everything else seems fine though)
>>
>> More to report later, but was excited that "something from the future"
>> (qmath.exe built almost a decade after the PC-5000 was sold) worked.
>>
>>
>> -SteveL
>>
>>
>>
>>
>> On Fri, Oct 18, 2024 at 6:35 PM Fred Cisin via cctalk <
>> [email protected]>
>> wrote:
>>
>> > On Thu, 17 Oct 2024, Steve Lewis wrote:
>> >
>> > > I follow all that (on the DEBUG.COM notes) and appreciate the notes -
>> > that
>> > > will save some time, I look forward to trying a few things out
>> tomorrow.
>> > >
>> > > I forgot to do VER explicitly, but on boot up it is saying MS-DOS
>> 2.00.
>> > >
>> > > And just now, I recalled that on github there is MS-DOS source (and
>> > bins) -
>> > > I think Dave's Garage, he recently did a video on building and booting
>> > > MS-DOS 4.0 from that source.   Maybe I should use this as an excuse to
>> > try
>> > > a 2.0 build?    Or least, reading through the FORMAT.ASM, I see all
>> the
>> > > DOSVER checking stuff - helps confirm patch addresses, or maybe try
>> just
>> > > recompiling that one utility without this check.
>> > >
>> > >
>> > > Reading through the CONFIG.txt in the MS-DOS 2.0 github repo, it's
>> > > interesting near the end:   (the use of forward slash instead of
>> > backslash,
>> > > ha! and just above this, the comments mention /dev/<dev>)
>> > >
>> > > "A typical configuration file might look like this:
>> > >
>> > > BUFFERS = 10
>> > > FILES = 10
>> > > DEVICE = /bin/network.sys
>> > > BREAK = ON
>> > > SWITCHAR = -
>> > > SHELL = a:/bin/command.com a:/bin -p"
>> >
>> > GOOD
>> > So, you should be able to patch FORMAT 2.11 ti work on the DOS version
>> > that is running.
>> >
>> > BUT, whether Format /S  or SYS  will work remains to be seen.
>> >
>> >
>> > I have seen cases where the opening banner does not quite match the
>> stored
>> > version number, such as 4.01 V 4.00
>> > and a conditional jmp needs an exact match.
>> >
>> >
>> > So, definitely run VER
>> >
>> > and/or
>> > in debug  A(Assemble)
>> >
>> > MOV AH,30
>> > INT 21
>> > INT 3    ; ends program and displays registers
>> >
>> > and see what it shows in AX
>> > (running that in CMD of my Windows 7 gives 0005 (5.00)!)
>> >
>> >
>> > One of the early homework assignments when I taught PC Assembly was to
>> go
>> > into DEBUG and patch LINK.EXE and EXE2BIN.EXE to eliminate DOD version
>> > checking.
>> >
>> >
>> > --
>> > Grumpy Ol' Fred                 [email protected]
>> >
>>
>

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