A2090a Setup Notes 6 April 2020 A Hoffman The A2090a (which is A2090 fitted with auto boot ROMs) normally has a limitation of 256MB drive sizes. This needs EPROMs U50 and U51 (27C64) reprogrammed with A2090A-U50-315098-01-HI_PATCHED A2090A-U51-315097-01-LO_PATCHED The following notes were used to get a v5 SCSI2SD auto booting on A2000 with OS1.3 Reference: http://eab.abime.net/showthread.php?t=82162 1. Configure SCSI2SD as a single 500MB drive, SCSI unit 0, slow mode is enabled, but that might not be necessary 2. Connect to SCSI2SD A2090a SCSI port, the A2090a already has SCSI termination at its end, the SCSI2SD needs a power source connected since A2090a doesn't supply termination power, the SCSI2SD needs termination enabled 3. Write A2090a.dms to a disk, this is essentially a bootable WB1.3 disk, it differs to the usual one found online as /Devs/Mountlist is replaced with: /* MountList entries for single SCSI unit 0 Hard Disk, this translates to unit 3 on the A2090a */ RES2: Device = hddisk.device Unit = 3 Flags = 0 Surfaces = 12 BlocksPerTrack = 64 Reserved = 2 LowCyl = 0 ; HighCyl = 1 Buffers = 1 BufMemType = 0 # DH2: Device = hddisk.device Unit = 3 Flags = 0 Surfaces = 12 BlocksPerTrack = 64 FileSystem = l:FastFileSystem Reserved = 2 LowCyl = 21 ; HighCyl = 1024 Buffers = 50 GlobVec = -1 Mount = 1 DosType=0x444F5301 BufMemType = 0 # 4. Boot from the floppy disk, open Shell 5. Enter: mount RES2: 6. Enter: prep RES2: Select 0 for custom drive definitions, then for the next 3 items use: Number of heads = 8 Number of cylinders = 1024 Number of Sectors per track = 64 For all the remaining prompts press enter to accept the default At the final prompt, enter Y to proceed 7. Reboot the system and boot from the floppy disk again During reboot the system may complain of non DOS disk, volume not validated or appear to hang at the "Release 1.2" prompt, just ignore these and if stalled at "Release 1.2" then leave it for 5 minutes or so as it is attempting to revalidate the volume 8. Once booted, open Shell 9. At the command prompt enter: format drive DH2: name System quick During format the prompt "Volume System is not validated" can appear and the system may appear to be frozen, leave it for a few minutes and eventually the format will complete and the prompt will go away, the hard drive is now ready for use, partition size will be 261MB when you enter: info 10. Change floppy disks to a standard copy of Workbench 1.3 and reboot system, open Shell 11. Copy workbench to the hard drive using: copy df0: System: all 12. When finished, remove the disk and reboot, after which it should boot normally to Workbench 1.3 from hard drive ------------------------------------------------------------------------------- Notes: SCSI unit 0 uses RES2: and DH2: [unit 3 on A2090a] SCSI unit 1 uses RES3: and DH3: [unit 4 on A2090a] SCSI unit 2 uses RES4: and DH4: [unit 5 on A2090a] etc... These numbers are fixed and cannot be changed. The SCSI Lister tool on the A2090a disk only appears to work correctly once the drive is fully set up. When any drive is first connected but not prepped, then SCSI Lister will hang at certain points or state Unknown Error. If you have any different numbered SCSI devices, or add more, then you'll need to edit /Devs/Mountlist accordingly and add both a RESx: and DHx: according to the new SCSI units. Then on the command prompt you need to set each of these up using: mount RESx: then prep RESx: then (after reboot) format drive DHx: name Whatever quick For other disk/partition sizes use this calculator: http://www.csgnetwork.com/mediasizecalc.html The drive geometery data possibly needs to be copied to /Devs/Mountlist, not sure how necessary that is Using larger partition sizes generally results in the system after reboot complaining of: Error validating disk System Key -1 out of range And the disk being permanently invalid. No idea how to fix that, there appears to be a lot of limitations everywhere with trying to use anything beyond 200MB or so, even with the supposedly "fixed" ROMs in the A2090a