80-Bus News

Conclusion

I have no hesitation in recommending the MAP RAM card, despite the poor documentation. It is well engineered and works perfectly. With the growing popularity of virtual disks, it is likely to be a success. I look forward to seeing the next MAP product which is rumoured to be a memory mapped (paged out) 80 by 25 video card complete with an optional floppy disk controller which is software compatible with the Gemini GM809 disk controller!!! Gemini are rumoured to be producing a new memory card, but there is no information yet on how much memory it will have. My guess is that 256K is the minimum they will consider, and 512K could be possible! Anyway, it looks as if Gemini are getting some tough competition, which will no doubt be good for us all.

The MAP RAM is available from MAP 80 Systems LTD., as advertised in this issue.

In the December 1981 issue of INMC 80 (Issue 5 and last) I wrote an article about SYS. At that time I said that I had just finished a new version which supported the Gemini double density disk card. That seemed quite a step forward at the time, but a lot has happened to SYS in the last year, and a new version, Vi5.0 has just been released, so I thought it would be a good time to bring you up to date on the latest developments. First I will just give a few hints of what it now includes:–

Nascom ––– Gemini GM811 ––– Gemini GM813 ––– Galaxy ––– Quantum
Micropolis ––– Winchester ––– Shugart ––– ‘Shugart Compatible’ ––– 8 Inch
Pertec ––– Cromemco ––– Rml ––– Xerox ––– Superbrain ––– Rair
Virtual Disk ––– Virtual Boot ––– MAP 256K ––– Memory Mapping
Megabyte Of RAM Systems ––– Configuration Messages
‘Fixed’ Screen Editing ––– Screen Paging Control ––– Screen Dump

First a brief description of what SYS is, for those few of you who are not yet using it!

SYS is a CP/M program which replaces the BIOS of the CP/M system with an expanded BIOS which has many additional features. The BIOS is the part of CP/M which deals with input and output.

SYS can be executed automatically on Reset or Cold Boot and it automatically relocates the new BIOS to match whatever size CP/M system is in use. This means that it can easily become an integral part of the computer system.

SYS is always stored on disk with the standard name of SYS.COM, but there are a vast number of possible configurations which support different hardware requirements. These are selected by conditional assembly.

SYS may be used on Nascom or Gemini computers. It requires a Gemini GM809 or GM829 double density disk card. At present it supports Version 2.2 of the CP/M operating system.

SYS contains two versions of the disk software. The first of these supports only Pertec 35 track 48 t.p.i drives or Shugart compatible 48 t.p.i drives (if the time constants are changed to suit). However it has the advantage that it is able to provide support for a whole range of disk formats which are described below, allowing data to be exchanged with many other types of computer. The second incorporates the Gemini standard disk software which includes support for Winchester hard disks and standard eight inch floppy disks, aa well as further options for Pertec, Micropolis, and other ‘Shugart compatible’ 96 t.p.i five inch disk drives. See the suppliers note on Winchester version availability at the end of the article.