Tag: CP/M

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Sorcerer ROMPAC Basic Games on CP/M

Posted on by Graham

There were a number of games on the Sorcerer disks that fired up fine, but there were a large number that did not.

I got some help from Alan Laughton (Microbee Technologies) to work out what was going on. He spotted that the files contained basic. They were com files – so quite different from the basic files that you would load into the disk basic.

Browsing through the manuals and other data, it became clear that the ROMPAC BASIC work area had been set up in such a way as to allow programs to be saved and loaded with CP/M.

The ROMPAC basic has a lot more memory available to it than the disk basic. It doesn’t waste space on the interpreter or the operating system.

The first entry in the com file is a jump to the warm start area of the basic ROMPAC. This failed on my machine because i had no ROMPAC.

What i did have, though, was a 8k S-100 RAM card (Solid State Music MB6) which i could locate at the same address as the ROMPAC at C000.

The card, predictably, failed the Sorcerer Monitor RAM test, but the offending IC was found and replaced.

I tested it out by using ddt to load the ROMPAC which was moved up into the RAM card. Following reset, the “RAMPAC” was found and basic fired up.

“bye” at the basic prompt returned to the Sorcerer monitor and GO BC00 started CP/M again. One of the previously failing com files was loaded and sure enough it ran!

After that, i wrote a very short program that replaced the ddt step. This allowed another 23 games to execute.

I’ve since created to couple more which load the development and word processor ROMPAC code into the RAMPAC.

The memory card had a facility to write protect the contents, so i added a switch to the expansion unit to enable it.

Transferring ROMPAC Basic Programs from CP/M to Tape

Posted on by Graham

Some of the basic games that have been stored as CP/M com files are missing from the sorcerer archives at Microbee Technologies (Alan Laughton is the curator) so i went through the process of transferring them back to audio files.

These were translated to wav files as follows:

  1. At monitor GO BC00 to boot up CP/M.
  2. Load the basic rompac (LDRAM).
  3. Reset – starts basic.
  4. Bye to return to monitor.
  5. SE T=1 to set 300 baud.
  6. GO BC00 to boot up CP/M.
  7. Load up the game eg A>LAIR to load up LAIR.  This starts up the ROMPAC basic.
  8. Load up Audigy on a PC.
  9. Set recording gain to max and the input to mono.
  10. Connect LINE IN on PC to AUX on Sorcerer.
  11. Start recording and enter CSAVE LAIR.
  12. When the sorcerer comes back with READY stop the recording and trim if necessary.
  13. Apply a good 20dB of gain to maxout and square up the waveform.
  14. Export the audio to a wav file.

Check as follows:

  1. Connect the PC LINE OUT to the input of the external amp.
  2. Connect the external amp output to the EAR input of the Sorcerer.
  3. Set Audigy playback volume to max. 
  4. Watch the EAR input with a scope and back off the Audigy volume until the waveform is clean and square.
  5. CLOAD LAIR.
  6. Hit play on Audigy.
  7. The title should be shown in less than 30 seconds.
  8. By the time the audio is complete, the sorcerer should say READY.
  9. RUN and enjoy.

If you want to do another then breakout with ^C, BYE to return to monitor and GO BC00 to boot CP/M.

Adding SCSI2SD to AMPRO Little Board plus

Posted on by Graham

I used a scsi2sd card with a 256MB sd card.

This took me a bit longer than I expected because I didn’t read the instructions.  CP/M needs to be configured to have some hard disk buffer space, otherwise the format fails mysteriously.  I changed it from 60k to 56k.  That allows room for the maximum 88MB of total disk storage.

The hformat program allowed for different controllers but after some experimenting I found success with the Seagate ST-225N hard disk. 

+-----

Form                 5.25"/HH              Cylinders     615|     |     |

Capacity form/unform    21/   25 MB        Heads           4|     |     |

Seek time   / track  65.0/20.0 ms          Sector/track   17|     |     |

Controller           SCSI1 SINGLE-ENDED    Precompensation

Cache/Buffer               KB              Landing Zone      670

Data transfer rate          MB/S int       Bytes/Sector      512

                      1.500 MB/S ext ASYNC

I set up sd2scsi with 7 drives each with 615 x 4 x 17 = 41820 sectors of 512 bytes.

I used hinit (with burst mode) to set up 2 partitions on drive 0 and drive 1:

  • 8192k
  • 8192k

This needs to be done on every boot (really? yes) but an alias can be created:

alias

HINIT YD010 AF8192 AG8192, YD110 AF8192 AG8192,.

hardinit

then another alias that does this and swaps the drives over:

alias

HARDINIT; SWAP AF BG CH DI; STARTUP

HSTART

Startup can contain whatever is wanted, eg a menu program.

HSTART can be run on boot by adding at item 5 in the config program.

Copy the system track from the boot floppy to the hard disk using SYSGEN (watch out for the letter swapping).

Less than obvious (it’s in a separate section of the hard disk software manual right at the end) are instructions for autostart, noting HGEN in particular.:

When the system starts, it looks for a boot floppy. If it finds it, then it will boot from it.  If it doesn’t find it, in about 10 seconds it will boot from the first hard disk partition.  For some reason it keeps looking for a disk in the first floppy disk drive.  If you give it one it stops but does nothing with the disk.