TRS-80 Zaps – DOS – TRSDOS v6.x (Unofficial)

Enable Drive :2

PATCH BOOT/SYS.LSIDOS (D02,84=C3:F02,84=C9)


Enable Drive :3

PATCH BOOT/SYS.LSIDOS (D02,8E=C3:F02,8E=C9)


Force FORMAT to prompt for the number of sides

PATCH SYS0/SYS.LSIDOS (D00,81=11:F00,81=31)


Prevent the DIR command from clearing the screen (TRSDOS v6.00.00)

PATCH SYS6/SYS.LSIDOS (D07,55=BD:F07,55=1C)


Replace the LIB command word “REMOVE” with the word “KILL” (TRSDOS v6.00.00)

PATCH SYS1/SYS.LSIDOS (D01,C8=4B 49 4C 4C 20:F01,C8=52 45 4D 4F 56 45)


Allow TRSDOS 06.02.00 level AN to format a disk with garbage data on it

This will allow TRSDOS 06.02.00 level AN to format a disk with garbage data on it left over from the certification process, or a “software bulk-erase”. Please note that these patches merely “band-aid” the problem, and the disk should really be properly bulk erased with a bulk tape eraser.

It is believed that the problem is related to the disk driver, specifically that the read status loop at X’0E70′ to X’0E75′ may not terminate on a “CRC error during sector header read” error passed back from the FDC. It is not possible to patch the driver, and a true solution must wait for the next re-assembly of the system.

. FORMATA/FIX - 04/23/85 by --jjkd--
.
. Optional patch to FORMAT on TRSDOS 06.02.00
. This patch is for FORMAT from TRSDOS 06.02.00 Level AN only.
.
. This patch forces FORMAT to skip the "is this disk formatted"
. test when formatting to prevent a system hang if farkled data
. is present on the disk. You should bulk erase the diskette.
.
. Use build to enter the patch lines and apply using
.
. PATCH FORMAT/CMD.UTILITY FORMATA/FIX
.
X'3492'=00 00 00 C3
.
. End of patch

. FORMATB/FIX - 04/23/85 by --jjkd--
.
. Optional patch to FORMAT on TRSDOS 06.02.00
. This patch is for FORMAT from TRSDOS 06.02.00 Level AN only.
.
. This patch forces FORMAT to skip the "is this disk formatted"
. test when formatting a disk if ABS parameter is specified.
. This is to prevent a system hang when farkled data is
. present on the disk. You should bulk erase the diskette.
.
. Use build to enter the patch lines. Apply using the command
.
. PATCH FORMAT/CMD.UTILITY FORMATB/FIX
.
X'3492'=CD 16 3A
X'3A16'=3A 27 35 B7 C0 CD 27 2A C9
.
. End of patch