Summary

Add an 8086 desktop computer from 1983, IBM Multistation 5550 (1st gen) machine.

The IBM 5550 was launched with three models:

• 5551-Axx: 12" monochrome CRT with 16x16 font
• 5551-Bxx: 15" monochrome CRT with 24x24 font
• 5551-Cxx: 14" color CRT with 16x16 font

These first-gen models have 1-3 DSQD diskette drives. You need select "Type: 5.25" 720k" in the Settings dialog - Floppy & CD-ROM drives. Currently, the emulator only supports the model B configuration without hard disk.

The architecture is derived from both the PC/XT and 6580 Displaywriter System. The IBM 5550 has different IRQ assignments. This means the normal DOS cannot run on that system. It requires a 5.25" bootable disk with a strange format written in the reserved sector. I only have IBM DOS version K3.44 with 3.5" 720k format. It cannot run because its reserved sector has a different format. I had to make another bootable DOS disk to fit the format with this machine.

Checklist

• Closes #xxx
• I have tested my changes locally and validated that the functionality works as intended
• I have discussed this with core contributors already
• This pull request requires changes to the ROM set
  • I have opened a roms pull request - https://github.com/86Box/roms/pull/changeme/
• This pull request requires changes to the asset set
  • I have opened an assets pull request - https://github.com/86Box/assets/pull/changeme/

References

• https://ardent-tool.com/IBM_5550/
• http://adb.arcadeitalia.net/dettaglio_mame.php?game_name=ibm5550

Screenshots