5 ms·

Well, not too many errors in that article. The section of "Going Multiuser" is a bit confused. After referring to CDOS-286 (aka FlexOS-286) it says: "DR ada

Well, not too many errors in that article. The section of "Going Multiuser" is a bit confused. After referring to CDOS-286 (aka FlexOS-286) it says: "DR adapted this to create Concurrent DOS-386 Concurrent DOS-386, [...] : a full 32-bit OS" Concurrent DOS-386 (which became Real/32 and friends) was derived from the original MP/M (multi user CP/M code, which spawned DR-DOS). That became Multiuser DOS. That line was not derived from FlexOS-286 (aka CDOS-286), which already had multi-user capabilities (each process had an 8 bit user-id and an 8 bit group-id). I'm not sure if that is suggesting FlexOS-386 was a full 32-bit OS, as it was not, however that is not obvious without the SBK. FlexOS-386 was most of FlexOS-286 (hence 16-bit) but with some parts (e.g. memory manager) being 32-bit. As to Concurrent DOS-386, I guess that was as "full 32-bit" as windows 95 was, i.e. not fully, but sort of, depending upon what drivers were present, and which APIs were used.

VogonPoetry 4y ago
This comment is confusing and perhaps misleading. The code that creates CP/M-86 (not multi-user) and CCP/M-86 (multi-user) are very similar. Some versions are publicly available. It is possible to download and compare. All Multiuser capabilities of CP/M, MP/M, CCP/M were for a 4-Bit User (0x0 to 0xF), expressed directly in the stored filesystem FCB format, set by the TPM and inherited by processes. Some fallback file search support existed to User 0 for System Files. No "group" identity ever existed for CP/M. Please double check the CCP/M OS documentation which is available. I re-read to (re)confirm my memory. (before my involvement...) CCP/M-86 3.1 existed. Supported only CP/M style media. CCP/M-86 4.1x existed. Supported only CP/M style media. Internal hints of CDOS :-). CCP/M-86 5.x existed. Supported CP/M and DOS media. Re/Co-branded Concurrent-DOS 5.x. CDOS 6.x existed. Supported DOS media. CP/M media only via CPM.CMD. At the time there were OTHER 286 architectures than the PC that DRI Supported. There was an interesting one, by Jarogate (Liam antennae alert!) - the Sprite. It was many times faster than other platforms, so it was being used by DRI for some primary development work. It was a modified S-100 based system and supported a full 16MiB of memory. But CDOS could not use it... As a Jarogate intern I spent a few weeks during a 198x summer with a rented HP logic analyzer working out what LOADALL (and other opcodes) did. This was based on some photocopy-fax-phlotocrapy-pfrax almost illegible document titled "MIPO News" which had teaser info, but not much more. At the end of my research I provided an ASM file of what LOADALL did and how to use it... I'm pretty sure it was given to DRI. CDOS 6.x XM. existed. Supported DOS media. LIMS memory + [LOADALL HACK] If you had a Jarogate Sprite running CDOS 6.2 XM, then it supported a full 16MiB of memory. I still have my Sprite, but it is not currently running :-( due to controller / disk problems. The Jarogate sprite used an AMD 12Mhz CPU. I do not know how this maps to the Intel versions. But, I think this is where some of the compatibility problems for DR started! The virtual console system of CCP/M was revolutionary and amazing. It does not get enough credit. There are perhaps other untold stories of how DRI was trying to move away from hand crafted ASM and PL/M to other high level languages.
lproven 4y ago
[Article author here] This piece resulted from something a reader pointed out in response to my earlier story on the new licence agreement, linked below. Since then, one of the authors of Real/32 has responded to me, with some fascinating clarifications.

VogonPoetry 4y ago

This comment is confusing and perhaps misleading. The code that creates CP/M-86 (not multi-user) and CCP/M-86 (multi-user) are very similar. Some versions are publicly available. It is possible to download and compare. All Multiuser capabilities of CP/M, MP/M, CCP/M were for a 4-Bit User (0x0 to 0xF), expressed directly in the stored filesystem FCB format, set by the TPM and inherited by processes. Some fallback file search support existed to User 0 for System Files. No "group" identity ever existed for CP/M. Please double check the CCP/M OS documentation which is available. I re-read to (re)confirm my memory. (before my involvement...) CCP/M-86 3.1 existed. Supported only CP/M style media. CCP/M-86 4.1x existed. Supported only CP/M style media. Internal hints of CDOS :-). CCP/M-86 5.x existed. Supported CP/M and DOS media. Re/Co-branded Concurrent-DOS 5.x. CDOS 6.x existed. Supported DOS media. CP/M media only via CPM.CMD. At the time there were OTHER 286 architectures than the PC that DRI Supported. There was an interesting one, by Jarogate (Liam antennae alert!) - the Sprite. It was many times faster than other platforms, so it was being used by DRI for some primary development work. It was a modified S-100 based system and supported a full 16MiB of memory. But CDOS could not use it... As a Jarogate intern I spent a few weeks during a 198x summer with a rented HP logic analyzer working out what LOADALL (and other opcodes) did. This was based on some photocopy-fax-phlotocrapy-pfrax almost illegible document titled "MIPO News" which had teaser info, but not much more. At the end of my research I provided an ASM file of what LOADALL did and how to use it... I'm pretty sure it was given to DRI. CDOS 6.x XM. existed. Supported DOS media. LIMS memory + [LOADALL HACK] If you had a Jarogate Sprite running CDOS 6.2 XM, then it supported a full 16MiB of memory. I still have my Sprite, but it is not currently running :-( due to controller / disk problems. The Jarogate sprite used an AMD 12Mhz CPU. I do not know how this maps to the Intel versions. But, I think this is where some of the compatibility problems for DR started! The virtual console system of CCP/M was revolutionary and amazing. It does not get enough credit. There are perhaps other untold stories of how DRI was trying to move away from hand crafted ASM and PL/M to other high level languages.

lproven 4y ago

[Article author here] This piece resulted from something a reader pointed out in response to my earlier story on the new licence agreement, linked below. Since then, one of the authors of Real/32 has responded to me, with some fascinating clarifications.