Questions tagged [cp-m]

For questions related to the CP/M operating system by Gary Kildall.

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What was the retail price of CP/M?

In the early days of the IBM PC, it was offered with a choice of four different operating systems including PC-DOS for $40 or CP/M for $240. Customers looked at what appeared to be essentially ...
rwallace's user avatar
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13 votes
3 answers

What are the names of the computers, that were used in the CP/M advertisement?

I am reading the article about the CP/M operating system and wonder which computers are displayed in this picture. I have recognized the "IBM PC" only - in the middle.
MiniMax's user avatar
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12 votes
3 answers

Why did CP/M require RAM in the bottom part of the address space?

A Z80 on RESET, starts executing from 0x0000. This is why the ZX machines and so many others have ROM at the bottom of the address space. Presumably an 8080 is the same. But as I recall, a CP/M binary ...
Omar and Lorraine's user avatar
15 votes
4 answers

Is there a way to execute CP/M binaries on a modern Linux computer

I have a few old programs/games which I'd like to run today. As there is Wine for running Windows programs, I wondered if there is a compatibility layer for CP/M. Obviously it would need to implement ...
Omar and Lorraine's user avatar
10 votes
8 answers

CP/M without floppy drive

I remember reading (at the time when it was current) in a hobbyist magazine about a ZX Spectrum modification to map RAM into ROM (not unusual), and implementing CP/M for it. The author ended the ...
Radovan Garabík's user avatar
11 votes
2 answers

Getting started with CP/M

I have a Commodore 128, but this is a platform-neutral question. I have a lot of experience with a lot of operating systems (including DOS, Linux, BSD and AmigaOS) but I never used CP/M much back in ...
Jim MacKenzie's user avatar
6 votes
2 answers

Are there any drivers available to use DivMMC on the Spectrum +3e with CP/M plus?

Heading says it all. I have a Spectrum +3 (with +3e ROMs if that makes any difference) with a DivMMC SD card interface. This works fine in +3e mode, but as I like to use the +3 with CP/M plus (...
tofro's user avatar
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44 votes
10 answers

Fastest non-emulated CP/M Z80-based computer ever built?

What were the fastest CP/M computers ever built? I'll restrict this to the Z80 variant of CP/M, no CP/M-86, CP/M-68k etc. Z80 compatibles with higher clock frequencies or more instructions/clock or ...
dirkt's user avatar
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25 votes
12 answers

Why did CP/M and MS-DOS use the BIOS instead of their own drivers to access hardware?

Modern versions of Windows (and other modern operating systems I suppose) have their own drivers to access hardware. But as I have read, in the old days, if CP/M or MS-DOS wanted to access hardware, ...
user7681202's user avatar
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3 votes
0 answers

How many CP/M machines ever shipped? [closed]

How many machines for which CP/M was the primary operating system (so not counting the Commodore 128) ever shipped? I would also be interested in knowing how many S-100 machines ever shipped. I get ...
rwallace's user avatar
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51 votes
7 answers

Why does the Commodore C128 perform poorly when running CP/M?

I have seen several claims of poor performance of the C128 when running CP/M, and would like to better understand these claims, especially in comparison to other CP/M machines of the early to mid-...
Brian H's user avatar
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24 votes
4 answers

How did the Apple II forward binary instructions to the Z80 software card with CPM?

Microsoft produced the Z80 Softcard for the Apple II enabling it to run CPM and many Z80 binary programs. This seems to be an unthinkable achievement. (For a kid who had an Apple IIe but was only a ...
hawkeye's user avatar
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7 votes
1 answer

Where can I find "Nemesis II", the sequel to "Nemesis", an old CP/M game?

In 1981, the "Nemesis" game was released for CP/M-based machines by Super Soft Inc., with the author attribution of Michael A. Pagels and Michael Q Hiller, and artist attribution of Diana J. Bush. ...
nijineko's user avatar
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12 votes
2 answers

Why did Amstrad choose such bank combinations for its all-RAM mode in +2A and +3 Spectrum computers?

The +2A and the +3 versions of the ZX Spectrum, made by Amstrad, had a new banking mode, called "special". This banking mode is entered by setting bit 0 of port 1FFD. When active, two bits from this ...
mcleod_ideafix's user avatar
16 votes
4 answers

Toolchain and workflow to build CP/M

Building my own version of CP/M has always been a fascinating to-do project. Problem is that it seems that the source code is not in regular assembler, but some kind of macro-assembler like language ...
mcleod_ideafix's user avatar