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Sirius One / Victor 9000

Posted on by Graham

The Sirius One was a moderately successful attempt to produce a 16 bit business machine using MS-DOS and CP/M-86. It was targeting a similar market of that of the IBM PC and although it runs the same operating systems as an IBM PC it is not a PC-compatible. Both machines were released in 1981.

The machine was sold as the Sirius One in some markets and as the Victor 9000 in others.

It was designed by Chuck Peddle, who is famous for designing the Commodore PET. It sold well in the UK and Europe.

The Sirius One did have some significant advantages over the IBM PC, including 800 x 400 pixel graphics, more sophisticated sound, and 600k single-sided 80 track 5.25″ drives.

The drives used variable speed to more efficiently use the longer outside tracks. The Apple Macintosh 3.5″ drives used a similar approach.

Furthermore, it has some nice touches like prompting for disks with icons and automatically detecting disks. It is happy to boot from either drive.

Soft keys for contrast and audio volume also add to the feeling that this computer is quite highly evolved for 1981.

Like the IBM PC, it had expansion slots – but not the same as the IBM ISA slots.

This particular machine was spotted by a ARC colleague, Mike, at a former recycling depot. It had been a little mistreated during the “about to be recycled” process, but nothing too severe.

It has 128k of memory on the main board and another 128k on an expansion card. Printer and serial ports were built in.

I think the monitor should be sitting on a pivot base, but that must have been lost along the way.

The Monitor required a simple cable repair after some rough treatment. It’s powered from the main unit.

I inspected the power supply. Somebuddy had powered the unit on fairly recently, probably in preparation for sale, and one of the line filter capacitors had smoked. I replaced 3 X and 2 Y capacitors. I load tested the power supply, and it was good to go.

The drives were in very good condition and i just cleaned and lubricated the rails. One drive light is a little dull.

Overall, the machine gives an appearance of far greater quality than an IBM PC. It comes apart easily.

Looking from the top: Floppy Disk Controller. Three spare slots on the expansion bus.
After Floppy Disk Controller has been removed: Motherboard
128k Memory Board

The keyboard is not great. The foam pads will need to be replaced (like a Compaq Portable or Kaypro II).

The machine did not come with any floppy disks. Fortunately, there are a lot of disk images available online.

Writing them is a bit of a challenge because of the unique format. They need to be written with an 80 track drive but with double density. I used a Panasonic JU-475-5. I tried another drive (Newtronics), but it seemed to only write reduced current for high density disk media.

Fluxengine supports the disk format and is happy to write it using a greaseweazle:

fluxengine write victor9k_ss --drive.rotational_period_ms=166.67 -i dbasemp.img -d drive:0

I found this method a little prone to crashes. The alternative is to convert the images to scp format using fluxengine, and then write the scps using greaseweazle. This does not verify the writes, though.

I now have the fluxengine hardware so that’s a third option to try.

The screen is very sharp. The brightness is controlled with soft keys. The monitor has an antiglare mesh built in.

Kermit works well.

At the Sirius end:

  • set parity none
  • set baud 9600
  • set default-disk b:
  • set flow-control xon/xoff

At the pc end (Windows 10 with CKW)

  • set file type binary
  • set baud 9600
  • set carrier-watch off
  • set flow-control xon/xoff
  • cwd <directory>
  • send <file>

Ampro Little Board Plus

Posted on by Graham

This is one of my current projects. It is based on the Ampro Little Board Plus which is a single board computer designed to be mounted on the back of a 5.25″ floppy disk drive.

It uses a Z80 processor running at 4MHz and includes two serial ports, one parallel port, a floppy disk controller and a SCSI controller. It runs CP/M 2.2 and is happy to boot off a floppy or hard disk. I’ve added a SCSI2SD to emulate several 20MB hard disk drives.

The user interacts with the machine using a serial terminal.

I started off with the two 40 track Mitsubishi drives shown but have been using a gotek (with FlashFloppy) for the software load.

Currently, i’m loading up a whole bunch of software from images created using cpmtools. Eventually this will be mounted in an external drive enclosure.

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.