HP250

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Revision as of 19:31, 7 July 2010 by 83.101.69.133 (talk)

HP 250 model 45252A (option 004,012)

  • 256K RAM
  • Internal 8" drive
  • External 9133 (3,5" floppy + 15MB hard disk)
  • 2631B Line printer

Condition

  • Generally works, boots, can print and access HD
  • Monitor has mold spots under the front glass. This looks ugly and makes text hard to read.
  • Currently no way to exchange programs/data with outside world.

To Do

  • Fix the mold spots. This is a known problem and has been discussed on the cctech mailing list. E.g. here and here.
  • Find a way to transfer software from the outside world. HP Museum has a number of disk images with software for the 250/260. But you need a 260 to copy them from 3,5" to 8". I see following solutions:
    • Connect an 8" drive to a PC (see [1]), convert the 3,5" teledisk images found on hpmuseum to 8" using the utilities found at [2] and write them to a real 8" disk.
    • Find a HPIB PC card suitable for HPDrive, convert the 3,5" teledisk images found on hpmuseum to 8" raw image and let the PC serve as a drive for the 250. This is better solution as it allows to boot the 250 should the 8" drive ever fail.

Notes

  • The 3,5" floppy cannot be used. The media test program included on the B.7.00 system disk shows an X2,3,0 device, but says it is unsupported. Also the hpmuseum.net claims a 250 cannot use 3,5" disks.
  • The ROM can only boot from 8" flex disc (see page 351/11 of the HP 250 Service Handbook found on HP Museum). Setting the thumbwheel switch on the processor board to 8. => it ran a memory test. So it must have the old ROMs for which there is no setting to boot anything else than the 9895 8" floppy or a 7910 hard disc.

HPDrive

I used HP Drive to exchange software between the 250 and the outside world.

For this I used a pentium 1 PC with Windows 98 and an ISA GP-IB card (NI AT-GPIB/TNT).

Also HPDir allows to access the files from the image or a real HP mass storage device. However I had some trouble using it, it seems to be not entirely compatible.