Running UNARC unexpectedly causes ROM drive to show 'NO FILE'

[codesmythe]

When running some of the ROM programs while testing a video driver, I ran across an issue where UNARC does something to make the contents of the ROM B: drive not available. This occurs when running the in-ROM CP/M 2.2 but not the in-ROM Z-System.

Quick steps:

• Select 'c' at the RomWBW boot prompt to run the in-ROM CP/M 2.2
• Do a 'dir' to see a file listing of ROM drive B:
• Run 'UNARC' with no command line arguments
• Do another 'dir' to see 'NO FILES'

My testing was on v3.5.0-beta.2, but I also see the issue on the 3.4.0 release "RomWBW HBIOS v3.4.0, 2024-04-20"

RomWBW HBIOS v3.5.0-beta.2, 2025-01-23

RCBus [RCZ80_std] Z80 @ 7.372MHz
0 MEM W/S, 1 I/O W/S, INT MODE 1, Z2 MMU
512KB ROM, 512KB RAM, HEAP=0x241A
ROM VERIFY: 00 00 00 00 PASS

CTC: IO=0x88 NOT PRESENT
LCD: IO=0xDA NOT PRESENT
SIO0: IO=0x80 SIO MODE=115200,8,N,1
SIO1: IO=0x82 SIO MODE=115200,8,N,1
DSRTC: MODE=STD IO=0xC0 NOT PRESENT
MD: UNITS=2 ROMDISK=384KB RAMDISK=256KB
FD: MODE=RCWDC IO=0x50 NOT PRESENT
IDE: IO=0x10 MODE=RC
IDE0: NO MEDIA
IDE1: NO MEDIA
PPIDE: IO=0x20 PPI NOT PRESENT
SD: MODE=PIO IO=0x69 DEVICES=1
SD0: NO MEDIA
CH0: IO=0x3E NOT PRESENT
CH1: IO=0x3C NOT PRESENT
FP: IO=0x00 NOT PRESENT

Unit        Device      Type              Capacity/Mode
----------  ----------  ----------------  --------------------
Char 0      SIO0:       RS-232            115200,8,N,1
Char 1      SIO1:       RS-232            115200,8,N,1
Disk 0      MD0:        RAM Disk          256KB,LBA
Disk 1      MD1:        ROM Disk          384KB,LBA
Disk 2      IDE0:       Hard Disk         --
Disk 3      IDE1:       Hard Disk         --
Disk 4      SD0:        SD Card           --


RCBus [RCZ80_std] Boot Loader

Boot [H=Help]: c

Loading CP/M 2.2...

CBIOS v3.5.0-beta.2 [WBW]

Configuring Drives...

        A:=MD0:0
        B:=MD1:0

        4099 Disk Buffer Bytes Free

CP/M-80 v2.2, 54.0K TPA

B>dir
B: ASM      COM : CLRDIR   COM : COMPARE  COM : COPY     COM
B: DDT      COM : DDTZ     COM : DUMP     COM : ED       COM
B: FAT      COM : FDISK80  COM : FILEATTR COM : FILEDATE COM
B: FLASH    COM : INITDIR  COM : LDDS     COM : LDP2D    COM
B: LOAD     COM : MBASIC   COM : NULU     COM : PIP      COM
B: PUTDS    COM : RELOG    COM : STAT     COM : SUBMIT   COM
B: SUPERSUB COM : TD       COM : UNARC    COM : XSUB     COM
B: ZAP      COM : ZCAL     COM : ZDE      COM : ZPATH    COM
B: ZSCONFIG COM : ZXD      COM : ASSIGN   COM : MODE     COM
B: RTC      COM : SYSCOPY  COM : XM       COM : FDU      COM
B: FORMAT   COM : SURVEY   COM : SYSGEN   COM : TALK     COM
B: TIMER    COM : CPUSPD   COM : REBOOT   COM : CPM      SYS
B: ZSYS     SYS
B>unarc
UNARCU  Universal Archive File Extractor   Version 1.0
Usage:
   UNARCU {DU: or dir:}arcfile{.typ} {DU: or dir:}{afn.aft} {{/}options}
An ambiguous output filename (or no filename)
 implies archive directory display.
An output DU implies file extraction.
An unambiguous filename implies type-out.
Options:
   N   Don't Page screen output.
   C   Check validity of archive.
   E   Erase existing files without asking.
   P   Send output to printer.
Examples:
   B0>UNARCU A3:SAVE.ARK *.*  ; list all files in archive SAVE in A3
   A0>UNARCU SAVE *.DOC N     ; list just DOC files with no pauses
   A0>UNARCU SAVE READ.ME     ; type the file READ.ME to the screen
   A0>UNARCU SAVE C3:         ; extract all files to directory C3
   A1>UNARCU SAVE B:*.DOC     ; extract DOC files to directory B1
   A0>UNARCU SAVE PRN.DAT P   ; send the file PRN.DAT to the printer
   A0>UNARCU SAVE *.* C       ; check validity of all files in archive
Copyright 1986, 1987 by Robert A. Freed.
B>dir
NO FILE
B>     

[wwarthen]

Thanks for reporting this @codesmythe. I was able to reproduce the problem under CP/M 2.2.

The problem does not manifest itself when using any other OS (CP/M 3, Z-System, etc.) even though ZSDOS uses a binary identical CBIOS. I am suspicious that the problem is with UNARC itself.

Note that this version of UNARC has a long history (it is not the original UNARC) and has been enhanced in many ways to handle Z-System, file date stamping, etc.

Lars Nelson did the latest updates to it in 2023. I will probably reach out to him and see if he can take a look.

Thanks, Wayne