Viewing Issue Advanced Details
ID Category [?] Severity [?] Reproducibility Date Submitted Last Update
05794 Misc. Major Always Dec 11, 2014, 22:54 Jul 20, 2017, 10:01
Tester demotester View Status Public Platform MESS (Official Binary)
Assigned To Resolution Open OS Windows XP
Status [?] Confirmed Driver pyl601.cpp
Version 0.156 Fixed in Version Build Normal
Summary MESS-specific 05794: pyl601, pyl601a: Disk reading failed!
Description Failed on disk reading... see steps below and attached picture.

Note: The driver has status working!
Steps To Reproduce mess pyl601 -flop1 system

Additional Information The other emulator (link below) reading the same disk without problems!
Regression Version
Affected Sets / Systems pyl601, pyl601a
Attached Files
png file icon pyl601.png (13,471 bytes) Dec 11, 2014, 22:54 Uploaded by demotester
png file icon 0000.png (5,012 bytes) Dec 12, 2014, 09:15 Uploaded by B2K24
png file icon 0001.png (3,980 bytes) Dec 12, 2014, 09:15 Uploaded by B2K24
There are no relationsihp linked to this issue.
User avatar
Dec 12, 2014, 05:17
I tried "sash" from the software list, and received the same error.

So, the bug is confirmed.
User avatar
Dec 12, 2014, 09:14
It seems to work as it should if you don't switch to A:\

The emulator link also does not demonstrate the need to switch drives.

If I enter DIR followed by GD, I get the Graphics Designer using MESS

Unless I'm not understanding something, it seems to work as it should.
User avatar
Dec 12, 2014, 10:21
edited on: Dec 12, 2014, 13:34
It does not prove anything ... because you get the same if there is no disk in drive. (mess pyl601)

The C: drive is ram-drive created from rom-disk driver!

The point is that it fails reading a disk inserted in floppy drive!

And you can compare / test the same on mentioned other emu. (On other emu when a disk is inserted in drive A: it will prompt to A:, not C:!)

Note: The other emu in floppy folder contain same disks as in softlist but with .imz extension (.imz = .zip) !!!

Btw, try to run C:GD on pyl601a driver (mess pyl601a)! (it looks strange !?)
Some infos about pyl601 and pyl601a:

p.p.s (google_translated) quote:
1) Note on the ROM BIOS for the basic models Pldin-601 / 601U

 The archive is BIOS 2.50, and in the archive with the emulator Todor Todorov - BIOS 2.60. These BIOS there is a fundamental difference. The fact that early models Pldin-601 / 601U has at hardware error, which was that it was not in the line 40 and the symbol 42 (the last two characters are not visible and are not used). So, BIOS 2.50 is written for the case of 42 characters, and BIOS 2.60 - for the case of 40 characters, ie already corrected the error in hardware. Todor Todorov emulator emulates model Pldin-601 with 40 characters per line and it is only suitable BIOS 2.60, and the emulator archive - model with 42 characters per line, so it requires a ROM BIOS version 2.50 or later.

 For models Pldin-601A / 601M - also has a ROM 2.50 and 2.60, but they are mutually compatible, since Pldin-601A / 601M similar problems with iron was not.

Note: in Additional Information are mentioned the 3rd emulator! (so there are 3 other emulators in existence = total of 4 if counting MESS) (and each uses a different bios !?)

In addition... (google_translated) quote:
Archive contains 3 file - the contents of the ROM, which can not be directly read from Pldina:

keyboard.rom ROM with the data for the keyboard controller
video.rom Character generator ROM for the video to text font 8x8 (for models 601 / 601U)
video_a.rom Character generator ROM for the video to text font 8x16 (for models 601A / 601M)

Archive - 8x8 fonts from XBIOS (expansion BIOS). These fonts are used when the computer Pldin (any model!) Works in graphics modes. The archive
includes fonts as of version 3.00, as well as from version 3.02 UniBIOS.

User avatar
Dec 12, 2014, 22:18
edited on: Dec 12, 2014, 22:22
It functions exactly like the screenshots shows a the emulator's homepage:
Like b2k24, I can load, it gets put in RAMDISK (like other emul) and can start it.

What I don't see in MESS is the 'ability' to mount the loaded floppy (which goes by default in both programs into C:) - into A. Is it a text command? Is the other emulator also hacked in a way which doesn't allow A: to be directly mounted without use of this RAMDISK? It doesn't happen in the other emulator automatically unless you invoke the icon for it. Stands to reason there may be a command hardcoded into the bios which allows the ramdisk contents to be 'thrown' to the virtual A drive. How do the original machine work? Also, ply601a appears to be an alternate bios allowing 80 column text. It stands to reason that running stuff meant for40 columns might be doubled or otherwise offset greatly.

Unless there is someone that can in person accept or deny the way things boot on the actual machine with actual hardware and images. Someone should make a video or something to demonstrate its usage.

User avatar
Dec 12, 2014, 22:48
edited on: Dec 12, 2014, 23:51
In other emu is possible to see contents of the mounted floppy disk with changing from C: to :A: and DIR!

In MESS it fails, right? ... and this is a primary reason for opening this issue. (just remind the essential)

Who can better known this machine than the one who wrote this driver for it !?

What I know... this machine has "file-compatibility" with IBM PC / XT ... it can read/write (exchange) data from same floppy (not execute because it has MC6800) ... so the floppy fix should be very easy.

And there also exist another multi-emu that emulates all Pyldin-601 models:

User avatar
Apr 9, 2016, 18:27
Seems in .0172 version nothing changed... the system disk mounted on drive A: is not recognized (as any other)?
(again, do not mix with the drive C: that is working - the problem is drive A not drive C)

Note: the pyl601 driver has status WORKING!
User avatar
Apr 9, 2016, 20:56
demotester, please let me just note some things here regarding bug reports:

If a machine in MAME is not flagged as not working, in general, it is expected to work. That doesn't mean we don't expect bugs or that regressions of any type are not expected. Any bugs that are experienced get logged here and no matter how severe, if they are expected to be able to be fixed, the MACHINE_NOT_WORKING flag does not get added to source. Long story short, we don't have any reason to indicate this could not be fixed with some effort by a capable and interested developer so stressing that things STILL don't work or that something is not flagged doesn't help the process. This is akin to bumping a thread in a forum and won't grant you any favor.
User avatar
Apr 9, 2016, 22:02
Tafoid, thx for a nice explanation.

You are right that for all machines flagged as working, in general, it is expected to work. But then it also means that these problematic one had worked in the past, otherwise would not get closer to the status of working, I guess.

And yes, it is impossible to expect 100 percent emulation, even when it seems that is excellent, because it is simply the way it works.

But in a case when it is known what machines with the status working are "still" problematic, is not it at least weird to insist on status working when it is known to not working properly? (for what)

IMHO, a such machines should get another status before any of next MAME release. Maybe the new status should be f.e. "on repairs", "problematic", "not working properly" etc.
to know that there is a problem. Thus, retaining the status of working seems as if everything is still fine, and we know that it is not, except that the user still thinks it's okay. (a little annoying)
User avatar
Jul 20, 2017, 10:01
edited on: Jul 20, 2017, 10:52
As its known, the pydin 610 floppy disk is logically compatible with ibmpc drives, so according to that I have tested
current swlist of pyl601 on ibm5170 driver as drive B: with command DIR B: and got following results:

swlist = size ... readable result
sys1 = 360KB ... readable in ibm5170 driver only as 5.25DD
disk2-disk5 = 720KB ... readable in ibm5170 driver as 3.5 DD or 3.5HD
arch1-arch7 = 1440KB ... readable in ibm5170 driver as 3.5DD or 3.5 HD

Note that current pyl601 and pyl601a drivers has now only floppy as 5.25HD that cannot read above disks !?

Proposal: Maybe pyl601 and pyl601a drives should have also selection of floppy disk drives as ibm5170 driver to allow reading different disk formats !?

So how pyl601 computer should behave?

A: = drive A
B: = drive B
C: = rom system ram drive
D: = ram drive

If bootable disk is not present in drive A it boots system from rom and finish with prompt C.
If bootable disk is present in drive A it boots system from drive A and finish with prompt A.

A system on bootable floppy disk usually contains a newer version of uniDOS kernal than system in rom!
Floppys from swlist: sys1(360KB), system(720KB) and sash(720KB) are system bootable!