Scorpio News |
January–March 1987 – Volume 1. Issue 1. |
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| b) ^T,^P – | Send a Form Feed to printer, causing it to advance to top of next page, and reset BIOS lines per page count. |
| c) ^T,^R – | Reset IVC/SVC to 80 wide. Useful for the (very) rare time when screen corrupts or gets out of vertical sync. |
| d) ^T,^N – | Switch attached (Epson) Printer to Normal Print. |
| e) ^T,^C – | Switch Printer to Compressed Mode. |
| f) ^T,^S – | Reset Screen Paging Flag to 0, to enable paging if a ‘W’ or ‘K’ was issued and a Warm/Cold Boot is undesirable. |
| g) ^T,^T – | Pass ^T on to calling program. |
The listing above, on pages 48 and 50, shows in upper case part of the original BIOS code (MAP BIOS), and lower case shows the modifications, but note that the cursor definitions have been moved into CURON/CUROFF to fit in with other BIOS modifications.
If there is plenty of spare space in the BIOS, quite a number of printer support features could be incorporated, and even function key redefinitions.
I have detected a problem with BDOSZ. Recently I have added a Winchester disk to a Gemini system. Despite the fact that CP/M Plus is available, CP/M 2.2 on the machine in question has been customized extensively along the lines of this article and this operating system is still preferred for many purposes. Consequently I needed compatibility between CP/M 2.2 and CP/M Plus in Winchester support eventually cobbled together a CBIOS with all of the required features and compatible Disk format by using a couple of MAP CP/M 2.2 BIOS’s and some routines from SYS.
CP/M 2.2 at that stage had CCPZ and BDOSZ in operation. I then found that with CP/M 2.2 and CP/M Plus were treating the floppy drives the same in respect of the way the Directory Block allocation war being written, but wrote them differently to the Winchester. CP/M Plus was putting a 00 byte between block numbers on the Winnie directory, but CP/M 2.2 was not. After reverting to standard CP/M 2.2 BDOS the Directory on the Winnie was the same on both versions of CP/M. The 00 byte is not present on the floppy directory under either operating system but present on the Winnie under both. If anyone knows of a patch for BDOSZ to make it treat the Winnie properly, I would be pleased to obtain details.
Some useful References:
| 1) | Disks and CP/M | I.N.M.C.80 News No. 5 |
| 2) | Customizing your CBIOS | 80BUS News. Vol 2, Iss 1 |
| 3) | SYS-Latest Developments | 80BUS News. Vol 2, Iss 1 |
| 4) | SYS is dead – long Live ? | 80BUS News. Vol 2, Iss 4 |
| 5) | CBIOS Real time Clock | 80BUS News. Vol 3, Iss 6 |
| 6) | CP/M Features & Facilities | CPMUG U.K. Vol 1, No 1. |
| 7) | The BIO | CPMUG U.K. Vol 1, No 5. |
| 8) | The Console Command Processor | CPMUG U.K. Vol 1, No 8. |
| 9) | ZCPR Replacement CCP | CPMUG U.K. Vol 2, No 2. |
| 10) | The SB180 – Software | Byte. Oct 1985 |
| 11) | Soul of CP/M | Sams & Co. (U.S.A.) |
| 12) | Mastering CP/M | Sybex. (U.S.A.) |
| 13) | CP/M manuals. | Digital Research. |
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