Startup error code tables

The following is copied verbatim from the Apricot BIOS 3 Software Technical Reference Manual, Appendix A

Appendix A: Diagnostic Error Codes

When the system is booted up a check is made to see whether it is a cold or a warm start. If it is a cold (power-up) start the ROM resident diagnostic program is run to check the integrity of the hardware.

If an error is found the diagnostic program is terminated and the error number is shown on the start-up screen. See tables 1 to 4 for the appropriate computer.

The ROM BIOS enters the boot procedure, displays the start-up screen and after a timeout looks for a bootable disk. Boot disk errors are listed in table 5. Note that the screen display of an error from the diagnostics is overwritten by the boot procedure.

Both types of error are indicated by a large 'X' on the screen, together with a one or two digit error code.

Table 1. Apricot F Series diagnostics

Code Test description

25 RAM check. Check of system/display and extension RAM.
29 Z80 CTC. Does a register test of the clock chip.
33 CLOCK INT. Checks whether a clock interrupt can be generated.
22 SIO. Register test of the Z80 SIO.
28 FDC. Register test of the WD 2797 floppy disk controller.
35 DRIVE TEST. Checks whether Drive 0 exists and can be restored and stepped.
20 PROM. Calculates the checksum of the PROM and compares it to that stored at the start of the PROM.

Table 2. Apricot FP Portable diagnostics

Code Test description

25 RAM check. Tests the system and any extension RAM.
24 DISPLAY RAM. Checks the LCD display RAM. If any color RAM is found, that is also checked.
23 CRTC. Register test of the 6845 video controller. This test is skipped if no color RAM is present.
27 PIC. Register test of the 8259 programmable interrupt controller.
29 PIT. Does a register test of the clock chip.
33 CLOCK INT. Checks whether a clock interrupt can be generated.
22 SIO. Register test of the Z80 SIO.
28 FDC. Register test of the WD 2797 floppy disk controller.
35 DRIVE TEST. Checks whether Drive 0 exists and can be restored and stepped.
37 DMA. Tests the operation of the 8237 DMA controller by performing a memory move.
38 VOICE. Tests the 6301 speech processor, including a test of the 6301's internal RAM and ROM.
20 PROM. Calculates the checksum of the PROM and compares it to that stored at the start of the PROM.

Table 3. Apricot PC/Xi diagnostics

Code Test description

25 RAM check. Checks the system and any extension RAM.
24 DISPLAY. Checks the video pointer RAM.
27 PIC. Register test of the 8259 programmable interrupt controller.
23 CRTC. Register test of the 6845 video controller.
29 PIT. Does a register test of the clock chip.
33 CLOCK INT. Checks whether a clock interrupt can be generated.
22 SIO. Register test of the Z80 SIO.
28 FDC. Register test of the WD 2797 floppy disk controller.
35 DRIVE 0. Checks whether Drive 0 exists and can be restored and stepped.
34 IOP. Verified the ability of the 8089 I/O processor to move a block of memory.
20 PROM. Calculates the checksum of the PROM and compares it to that stored at the start of the PROM.

Table 4. Apricot Xen diagnostics

Code Test description

25 RAM check. Checks the system and any extension RAM.
24 DISPLAY. Checks the 800x400 monochrome video card, if present.
23 CRTC. Register test of the 6845 video controller, if 800x400 video card present.
27 PIC. Register test of the 8259 programmable interrupt controllers (master & slave).
22 SIO. Register test of the Z80 SIO.
28 FDC. Register test of the WD 2797 floppy disk controller.
34 DMA. Register test of the DMA chip.
29 CIO. Register test of the CIO.
40 PIT. Register test of the programmable interval timer (used as a baud rate generator).
39 WINI. Register test of the 7261 controller.
20 PROM. Calculates the checksum of the PROM and compares it to that stored at the start of the PROM.
55 EEROM. Checksum test of the EEROM.
33 CLOCK INT. Test if able to generate a Clock interrupt.

Table 5. Disk Error codes

Code Failure description

 2 Drive not ready or disk removed during boot.
 4 CRC error; corrupt sector format.
 6 Seek error; unformatted or corrupt disk or faulty floppy drive.
 8 Sector not found; unformatted or corrupt disk or bad load address in disk label sector.
11 Bad read; corrupt data field on disk.
12 Disk failure; disk hardware fault or media fault.
99 Non-System disk; not a valid boot disk or disk incompatible with drive or invalid load address.

Note: if another loadable disk is present and found this message will appear but only briefly.

ACT/Apricot

Startup error code tables