GUBBINS@RADC-TOPS20.ARPA (Gern) (06/07/88)
Pat Swayne's 1.2MB disk read patch is on page 53 of the JUN-86 issue of REMark Magazine. The PC-AT 1.2MB drive is a 5.25" version of the DSDD 8" drive (both electronically and timming), and so (with a special cable) can be directly connected to the Z-100 8" connection on the controller. The problem is in the formats used by the software. The Z-100 formats (and expects) the standard 8" (IBM) disk format of 77 tracks/side at 8 sectors of 1024 bytes. The AT high density format is 80 tracks/side at 15 sectors of 512 bytes. The Z-100 BIOS is table driven and so the patch simply finds and alters the table entries to either the standard Z-100 or AT type format. The FORMAT command would also have to be altered to format to the AT type on a Z-100 (no patches yet known). After running the patch, you can read and write to the AT type format (but not the Z-100 type), and running the counter- patch program, revert back to the Z-100 format. I do not have the programs typed in yet, if anyone has them, please post! Gern -------