Author Topic: commodore pc-40  (Read 5283 times)

bilbous

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Re: commodore pc-40
« Reply #15 on: September 12, 2007, 06:12:52 pm »
Must be a European thing I guess as I never heard of them making dos compatible equipment  available in Canada. I suppose I might have missed it though and they did have them available here. I think my Adam had an 8086 [or would that have been an '88?] in it but I could be mistaken.

Elvicat

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Re: commodore pc-40
« Reply #16 on: September 12, 2007, 06:20:13 pm »
urgh next problem is to install the whole dos 6.22 on the hd and that's gonna be a problem when it dosn't boot from 1.44mb disks... any ideas?

on the FCC codes and similair, only things i seem to find on it is S/N (serial) codes and it has no code at post just the bios name and version + the mem counter
« Last Edit: September 12, 2007, 06:33:57 pm by Elvicat »


mektar

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Re: commodore pc-40
« Reply #17 on: September 12, 2007, 07:08:52 pm »
Is it possible for you to temporarily take the hard drive out of the Commodore system and put it into a more modern computer and then install the OS you want using 1.44 MB floppy disks?

if you're able to do that then you might also want to consider configuring the system so that you can transfer files to and from the Commodore to another PC using a null modem cable or a parallel laplink cable. Kermit http://en.wikipedia.org/wiki/Kermit_protocol is a program that can perform terminal emulation and transfer files over a serial null modem cable. I use it to allow my 386 laptop running FreeDOS with 1 MB of ram to act as a dumb terminal for one of my FreeBSD PCs. I think it can run on a 286 as well though and it is very portable. I know InterSvr in MSDOS 6.22 can transfer files using a laplink cable but I'm not sure if you'll be able to easily do that between that and a PC running Windows for example.. I know there are third party non Microsoft programs that can be used for transferring files over a laplink cable in MSDOS too though. You might want to research that because you'll get much higher bandwidth out of a parallel laplink cable than a serial null modem cable. I've installed FreeBSD onto a 486 laptop I have using a laplink cable and it wasn't too bad.
« Last Edit: September 12, 2007, 07:43:01 pm by mektar »

bilbous

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Re: commodore pc-40
« Reply #18 on: September 12, 2007, 07:34:45 pm »
Make a boot floppy of the kind it will accept, fdisk and format the hard drive, copy all the installation files to the hard drive and install from them there. There may be an installation ini file you will need to tweak so that it knows to look on the hard drive. Actually I think that once the system has been created [format /s c: , I think] you can just copy the files from one installation to another so if you have a drive with 6.22 on it just make the boot floppy and then copy the files directly bypassing the installation program completely. In some cases the files may be too large for one floppy so you might have to create a self-extracting archive that spans disks. You do not need to make it self-extracting if you have a pkzip from the proper era.

The boot disk ought to have most of what you need to run dos anyway. If you are really lucky you might be able to run windows 3.1 hehhehe.

If you are unsure about creating an autoexec.bat and a config.sys get a hold of an old manual from a library or something. Last I looked my library still had that obsolete information.

mektar

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Re: commodore pc-40
« Reply #19 on: September 12, 2007, 07:44:52 pm »
Ya it'd be easier to simply boot off of a floppy disk it will accept if you can find one. But if not maybe Elvi can try what I proposed..

Elvicat

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Re: commodore pc-40
« Reply #20 on: September 12, 2007, 07:52:19 pm »
i don't think moving the hd is a option as it's not a ide drive but a mfm/rll drive and i have no nullmodem cables at all
i might however try and fix the files from a newly installed dos tho, that could actually work and i've sysed the hd so but it's only the basic boot disk sys so not much to use
and btw the 6.22 install refuses to use the hd even if i've copied over the install files to there, it just says to put in the orginal diskette and reboot and no a dos boot disk is not enough to use a it as the more advanced commands arn't there

*edit
right got dos 6.22 in and it seems to work so far  \\o// still i wonder if that comp should only have 640kb ram... i'm suspecting it has 1mb but how to activate it...
« Last Edit: September 12, 2007, 10:43:54 pm by Elvicat »


evil scotsman

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Re: commodore pc-40
« Reply #21 on: September 12, 2007, 11:57:43 pm »
To use the 'extra ram' above the 640Kb Dos limit, either XMS or EMS may be used depending on the machine and the size of RAM installed, you must adjust c:\CONFIG.SYS and add these lines below;

DEVICE=C:\DOS\HIMEM.SYS   (80286 with at least 64KB XMS)

and either

DOS=UMB                   (8086/8088 or less than 64KB XMS)

or

DOS=HIGH,UMB   (80286 with at least 64KB XMS)

for EMS try this in the CONFIG.SYS

DEVICE = C:\DOS\HIMEM.SYS
DEVICE = C:\DOS\EMM386.EXE RAM
SHELL = C:\DOS\COMMAND.COM C:\DOS\ /p

Using XMS is pretty certain to work, EMS may or may not, depending on memory and bios, at this age it's uncertain which will work best, so i'd keep a boot disk handy in case of any problems accessing the machine if you try EMS and can't get it to boot.

Another way to get Dos 6.22 to do this automatically is to run MEMMAKER.EXE which should examine the system, and decide on the best memory configuration, then rebuild the Config.sys and Autoexec.bat for you, been a long time since I used DOS, but from memory these are the options i'd look at.

edit*

Just realised, us over 40's have a use after all, we're the only ones apart from die-hard geeks who even remember that Bill Gates said that '640KB should be enough for anyone', and saddled us with a memory limit of 640Kb until we stopped using DOS.  :D
« Last Edit: September 13, 2007, 12:13:46 am by evil scotsman »
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Elvicat

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Re: commodore pc-40
« Reply #22 on: September 13, 2007, 12:23:45 am »
actually the bios is set to 640k but i'm not sure of the total size, there are a few chips stuck to the mobo then others that you can pop up if you wish
so the base mem is there but the over 1mb is 0 not really sure about how to check this stuff
i read somewhere there should be a jumper where you could set the mem to 512 + 512 but uh... hehe you know with nothing to go after it's abit hard


bilbous

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Re: commodore pc-40
« Reply #23 on: September 13, 2007, 07:25:40 am »
You could always try the mem command it has several options but should tell you what is installed. The memory chips are very likely soldered to the mb they might have readable values printed on them in which case you may be able to add them up. If the bios lets you set an arbitrary amount it should be safe to try a higher amount. I think the worst that could happen is it will report bad ram and possibly not boot. I might be wrong so take this advice at your own discretion. If it doesn't let you set an amount then it is likely 640 is all there is.

Elvicat

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Re: commodore pc-40
« Reply #24 on: September 18, 2007, 01:48:00 am »
found some litle info on this pc, it's not much but still
http://www.old-computers.com/museum/computer.asp?st=1&c=905
that's most of the commodore pc's


bilbous

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Re: commodore pc-40
« Reply #25 on: September 18, 2007, 07:36:24 am »
It is a good bet that these are your ram and/or video ram chips. Perhaps a search for the text printed on them will tell you more but they might not be available on the open net. An old electronics manual such as you might find in a library might be of use. Alternatively you could post a clearer picture --text clearly visible as much as possible-- and one of us might be able to tell you better. You should be able to just add up the numbers to get the total, which numbers is not always easy to discern.

Elvicat

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Re: commodore pc-40
« Reply #26 on: September 21, 2007, 02:01:31 pm »
well i took a closer look at the chips that i think are the memory.
the solded ones had these numbers on them.
MD81256-12, thats the same on all the solded ones but the second row of text is this
8629 m64 bc
8623 m47 bc
8627 m33 bc
8624 m67 bc

theres one or two of these chips in the "plugged zone" to but most of these have different text
8644, next line same chip
hm50256p-12

another chip
tms4256-12nl

thats as much as i could gather, theres 4 rows with 9 chips in each, counting both solded and inserted making it a total of 36 chips.


miadon

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Re: commodore pc-40
« Reply #27 on: September 21, 2007, 03:02:59 pm »
http://www.memoryx.com/ I find these people helpful with RAM questions.

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bilbous

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Re: commodore pc-40
« Reply #28 on: September 21, 2007, 07:23:09 pm »
well i took a closer look at the chips that i think are the memory.
the solded ones had these numbers on them.
MD81256-12, thats the same on all the solded ones but the second row of text is this

thats as much as i could gather, theres 4 rows with 9 chips in each, counting both solded and inserted making it a total of 36 chips.
How many soldered ones are there, they look to be  the memory chips I think, the 256 is a good indicator as it is 29, your 640k is 655360 in actuality.
Quote from: upgrading and repairing pcs
MB81256 is the chips part number which usually contains a clue about the chips capacity. The key digits are 1256 which indicate this chip is 1 bit wide, and has a depth of 256K. The 1 means that to make a full byte with parity you need 9 of these single wide chips.

The -12 is 12 nanoseconds the timing for the chip. So what I think you need to do is add up these chips, divide by nine (early pcs all used error checking) and multiply by 256k and that should tell you the amount in kilobytes of ram you have.

640 is an awkward number for these as it would seem you need 2.5 sets to reach that number. 18 chips would give you 512K. Is there perhaps a set of 9 with 128 markings on them?
Quote from: ibid
For example, in an IBM XT 286, which is an At-type 16-bit system, the last 128K of Bytes of memory on the motherboard  consist of a bank of only six chips, four are 64K-by-4 bits wide, and two parity chips are 1 bit wide, storing 18 bits.

Sounds about right to me.
« Last Edit: September 21, 2007, 07:35:39 pm by bilbous »

Elvicat

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Re: commodore pc-40
« Reply #29 on: September 21, 2007, 07:26:43 pm »
there are 18 soldered and 18 pushed in, 4 rows with 9 chips in each

Quote
So what I think you need to do is add up these chips, divide by nine (early pcs all used error checking) and multiply by 256k and that should tell you the amount in kilobytes of ram you have.
and this just confuses me even more as i just go back and forth with the numbers
« Last Edit: September 21, 2007, 07:30:51 pm by Elvicat »