[cctalk] Re: Booting from B: (Was: Getting QRST files onto
I sent this before, but it didn't show up on the list;
Part 1;
Which versions of DOS let you boot off B: ?
Obviously, NO command that you run in DOS (which would be after it has
booted), will change the boot sequence, which is before DOS is present.
Nor will such a change last through a boot (although MICROS~1 could have
included a tepid/partial boot, if they had wanted to.)
DRIVER.SYS achieved prominence in DOS 3.20. PC-DOS 3.20 was the first time
that IBM supported a 3.5" ("720K") drive. Several other companies, other than
IBM, already used 3.5" drives for laptops, such as Data General, Gavilan, etc.
with their own drivers in MS-DOS, particularly version 2.11, which was similar
to 2.10, but used by OEMs that needed to customize MS- DOS. In many cases,
the 3.5" disk formats that those companies created were different from what is
supported in DOS 3.20 http://www.xenosoft.com/fmts.html
IBM PC/JX was an IBM machine with 5.25" "720K" drives, but was never sold in
USA.
Because IBM's 5170, and most already existing 286 machines, did not include
"720K" as any of the options in the "CMOS Setup" for identifying what kind of
drive each physical drive was, DRIVER.SYS permitted creating a
logical/virtual/shadow drive that would share a physical drive, as E:, F:,
etc.
LASTDRIVE was also needed if you already had more than two floppy drives and a
HDD, to permit assigning drive letters past D:
Another alternative was DRIVPARM ! It was a CONFIG.SYS command to alter the
parameters of floppy drives, WITHOUT creating any new logical drives or drive
letters! DOS 3.20 and onwards.
Something that has always confused me:
DRIVPARM is documented in MS-DOS 3.20, but is not mentioned in the PC-DOS 3.20
documantation.
I used MS-DOS with DRIVPARM on a generic 286 machine, and it worked!
I used PC-DOS with DRIVPARM on a generic 286 machine, and it worked!
I used MS-DOS with DRIVPARM on a genuine 5170, and it failed, with a "BAD
CONFIG.SYS COMMAND" message (possibly mistaken on the exact wording)
I used PC-DOS with DRIVPARM on a genuine 5170, and it failed, with a "BAD
CONFIG.SYS COMMAND" message (possibly mistaken on the exact wording)
I used MS-DOS with DRIVPARM on a generic 286, with copy of the 5170 BIOS, and
it failed, with a "BAD CONFIG.SYS COMMAND" message (possibly mistaken on the
exact wording)
I used PC-DOS with DRIVPARM on a generic 286, with copy of the 5170 BIOS, and
it failed, with a "BAD CONFIG.SYS COMMAND" message (possibly mistaken on the
exact wording)
So, therefore, I concluded that DRIVPARM was incompatible with the IBM 5170
BIOS. But present in both MS-DOS 3.20 and PC-DOS 3.20, although it is
UNDOCUMENTED in PC-DOS.
Chuck has mentioned that if you insert 3 Ctrl-A characters, it will work
on most;
DRIVPARM ^A^A^A B: /F:2
--
Grumpy Ol' Fred ci...@xenosoft.com
[cctalk] Re: Booting from B: (Was: Getting QRST files onto
Resending Part 2 BTW, for the parameters for DRIVER.SYS, you can abbreviate the /t:80 /s:9 to "/F:2" (and later, "/F:720") /0 was "360K" /1 was "1.2M" /2 was "720K" anybody remember the numbers for 8"? /d:2 meant you wanted the logical drive to use the third physical drive, /d:3 meant you wanted the logical drive to use the fourth physical drive, /d:1 meant you wanted the logical drive to use the second physical drive, /d:0 meant you wanted the logical drive to use the firs physical drive, which you could do if you used a "360K" format on the disk in the "720K" drive in A: during booting. Machines that had "CMOS Setup" that supported 3.5" disk drives would let you use a 3.5" drive as A: And 5.25" "Quad" drives (NON-HD 96tpi, such as Tandon TM100-4, Teac 55F, or Shugart/matsushits 465) was generally indistinguishable to the PC from a 3.5" "720K". TRIVIAL nits on the webpage (URL that you posted): TRS80 Model II was 8" drives. (model 1 and 3 were 5.25") Although I have heard of somebody kludging "1.2M" drives on one, I haven't seen it. The picture identifying locations shows the FDC on the motherboard. It was on the FDC board, and "power connectors" is pointing at the drive internal data connectors; the power connectors are not visible in the picture, because they are underneath. "Ive heard stories that the 37-pin external adapter can be used to read/write older 8 disk drives, but I never saw this in person. 8 disk drives were a bit before my time." modifications are needed to the FDC board to do so. Flagstaff Engineering did so, and sold a modified FDC plus 8" drive. The configuration switches on the motherboard of 5150 and 5160 can be set for up to four drives, and those should be discussed? Yes, as mentioned, with extra floppy drives, demented INSTALL programs, such as MS-DOS 6.00, will insist on trying to install to your third floppy. SUGGESTION: a cheap vise works adequately for crimping flat IDC cables; I've even done them with a block of wood and a hammer, and with vise-grips. NOTE: when I say "720K", "360K", "1.2M", I am using those as NAMES for those disks, formats, and drives, not as necessarily the capacity. I am well aware that those names don't acknowledge that the "720K" drive is capable of other formats, ranging from 640K to 800K, (or even more with short gaps, mixed sector sizes, and/or other tricks). But, I have yet to see, other than listing sample model numbers, names for the drive that are simple, and less ambiguous. -- Grumpy Ol' Fred ci...@xenosoft.com
[cctalk] Re: Booting from B: (Was: Getting QRST files onto
> anybody remember the numbers for 8"? This is the official KB from MS on the topic: Standard Floppy Disk Formats Supported by MS-DOS === Article ID: 75131 - View products that this article applies to. This article was previously published under Q75131 SUMMARY By using DRIVER.SYS and/or the DRIVPARM command in the CONFIG.SYS file, you can select a variety of floppy disk formats for use with MS-DOS. The tables below describe the standard floppy disk formats supported by various versions of MS-DOS and show the switches used for DRIVER.SYS and FORMAT.EXE. MORE INFORMATION The tables below include information on the following: Number of heads (sides) Number of cylinders (tracks) Number of sectors per track Total number of sectors Number of free sectors Number of sectors per cluster Total number of clusters Number of sectors per FAT (file allocation table) Number of FAT copies Number of root directory sectors Number of reserved sectors Number of hidden sectors Number of bytes per sector Number of bytes per cluster Number of root directory entries The media descriptor byte for each format What recording density was used to create the floppy disk Under what MS-DOS version this format was first supported What parameter to use with DRIVER.SYS for this format What parameter to use with FORMAT.EXE for this format Whether or not the changed-diskette line is supported NOTES 1.The switches shown for DRIVER.SYS can also be used for DRIVPARM. Example: The line "Device=C:\DOS\DRIVER.SYS /D:1 /F:9 /C" in the CONFIG.SYS file specifies that floppy disk drive B is a 2.88-megabyte (MB) 3.5-inch floppy disk drive that supports the changed-diskette line. Example: The line "DRIVPARM=/D:1 /F:9 /C" in the CONFIG.SYS file specifies that the floppy disk drive B is a 2.88-MB 3.5-inch floppy disk drive that supports the Change line. Example: The command "FORMAT B: /F:720" formats a double-sided double-density 720K floppy disk in a 1.44-MB or 2.88-MB 3.5-inch floppy disk drive that is installed in the computer as floppy disk drive B. 2.The following charts refer to "Clusters," whereas MS-DOS 5.0 and later refer to "Allocation Units." These two terms are equivalent and describe the same data structure. 3.Multiple formats with the same DRIVER.SYS switch is NOT an error. 4.Multiple formats with the same media descriptor byte does NOT indicate an error. 5.Valid media descriptor bytes for MS-DOS are listed below: Byte Capacity Media Size and Type --- F0 2.88 MB3.5-inch, 2-sided, 36-sector F0 1.44 MB3.5-inch, 2-sided, 18-sector F9 720K 3.5-inch, 2-sided, 9-sector F9 1.2 MB 5.25-inch, 2-sided, 15-sector FD 360K 5.25-inch, 2-sided, 9-sector FF 320K 5.25-inch, 2-sided, 8-sector FC 180K 5.25-inch, 1-sided, 9-sector FE 160K 5.25-inch, 1-sided, 8-sector FE 250K 8-inch,1-sided, single-density FD 500K 8-inch,2-sided, single-density FE 1.2 MB 8-inch,2-sided, double-density F8 - Fixed disk 6.Both track and cylinder numbers are zero-based. For example, 360K 5.25-inch floppy disks have 40 tracks numbered 0 through 39. Similarly, head numbers and side numbers are also zero-based. For example, 360K 5.25-inch floppy disks have sides 0 and 1 (corresponding to heads 0 and 1). However sectors are one-based. For example, 360K 5.25-inch floppy disks have sectors numbered 1 through 9. Standard Floppy Disk Formats Supported by MS-DOS 3.5 Inch - Formatted Capacity 720K 1.44 MB 2.88 MB # of Heads (Sides) 22 2 # of Cyls (Tracks)80 8080 # of Sectors/Track 9 1836 Total # of Sectors 1440 2880 5760 # of Free Sectors 1426 2847 5726 # Sectors/Cluster 21 2 Total # of Clusters 713 2847 2863 # Sectors/FAT 39 9 # of FAT Copies22 2 # of Root Dir Sectors 7 1415 # Reserved Sectors 11 1 # of Hidden Sectors00 0 # of Bytes/Sector512 512 512 # of Bytes/Cluster 1024 512 1024 # Root Dir Entries 112 224 240 Media Descriptor F9 F0F0 Recorded Density Double High High MS-DOS Version Began3.20 3.30 5.00 DRIVER.SYS Switch /F:2 /F:7 /F:9 FORMAT.EXE Switch /F:720 /F:1.44 /F:2.88 Change-
[cctalk] Re: Booting from B: (Was: Getting QRST files onto
On 3/2/23 11:02, Ali via cctalk wrote: >> anybody remember the numbers for 8"? > > This is the official KB from MS on the topic: > > Standard Floppy Disk Formats Supported by MS-DOS > Japanese MS-DOS (used on NEC computers, mostly) used 1024 byte sectors in 8", 5.25" and 3.5" media. In fact, most USB floppy adapters support the NEC 1.23M format and Windows NT has understood it (given a capable drive) for many years. It's Microsoft, so why it's not included in the table is beyond me. For example, if you were to use a NEC APC (sold in the US) with 8" drives, you'd find this format. Sector size: 1024 Cluster size: 1024 Sectors/FAT 2 Media byteFE Root directory size 192 --Chuck
[cctalk] Re: Booting from B: (Was: Getting QRST files onto
It is indeed strange that, MICROS~1 never seems to acknowledge the existence of the NEC variant. And yet, it made sense to have the same disk format parameters for three sizes of disk. Unfortunately, the otherwise excellent table leaves out the lines for DRIVER.SYS and FORMAT specifiers (if such existed) There are, of course, MANY other variants of MS-DOS disk formats, but mostly created by OEMs, not by Microsoft, and particularly with MS-DOS 2.11 and 3.31 . For example, 80 track 5.25" DD formats, such as Tandy 2000, IBM PC/JX, Dec Rainbow, etc., and 3.5" disks, such as HP, Gavilan, Data General, etc., before DOS 3.20. http://www.xenosoft.com/fmts.html (includes formats other than MS-DOS, such as CP/M, P-System, NEC and other with the Microsoft "Stand-Alone BASIC") -- Grumpy Ol' Fred ci...@xenosoft.com anybody remember the numbers for 8"? On 3/2/23 11:02, Ali via cctalk wrote: This is the official KB from MS on the topic: Standard Floppy Disk Formats Supported by MS-DOS On Thu, 2 Mar 2023, Chuck Guzis via cctalk wrote: Japanese MS-DOS (used on NEC computers, mostly) used 1024 byte sectors in 8", 5.25" and 3.5" media. In fact, most USB floppy adapters support the NEC 1.23M format and Windows NT has understood it (given a capable drive) for many years. It's Microsoft, so why it's not included in the table is beyond me. For example, if you were to use a NEC APC (sold in the US) with 8" drives, you'd find this format. Sector size: 1024 Cluster size: 1024 Sectors/FAT 2 Media byteFE Root directory size 192 --Chuck
[cctalk] Using Gotek's to emulate RX50's.
Seems like it should be simple, but it is not. I have a pair of Goteks with the Flaashfloppy code and each one has a USB with 400k RX50 images on it. Both are set to drive 2, and a standard 40 pin floppy crossover cable allows me to emulate a pair of drives. Now, I want to replace the RX50 drive on my Pro/380 with this setup to allow it to install POS. However it does not work, the Pro fails startup with an error on the floppy controller board, and so far it looks like POS can't see the disks. So what is the difference between an RX50 and a pair of 5.25 drives, and is it possible for Flashfloppy to emulate whatever oddness is in a true rx50? CZ
[cctalk] Re: Using Gotek's to emulate RX50's.
Chris, I, too, tried a similar thing. It mostly worked until there was a need to switch quickly between the two drives (booting the diagnostics, for example). Then it worked strangely. What I believe may be going on is that the Pro is relying on the fact that, although there appear to be 2 drives attached, they are using the same head positioning -- they seek in parallel. I thought about hacking the Flashfloppy code to pay attention to the drive select and allow a single Gotek to emulate both drives (and take into account the parallel seeking), but I just ended up using a real RX50 to boot diagnostics and that was good enough at the time. The big problem is that the Flashfloppy would need to have 2 disk images mounted at once. There's a problem of limited RAM in the Flashfloppy, but there's also a problem of the UI which is really set up for only a single image. --Bjoren On 3/2/2023 3:25 PM, Chris Zach via cctalk wrote: Seems like it should be simple, but it is not. I have a pair of Goteks with the Flaashfloppy code and each one has a USB with 400k RX50 images on it. Both are set to drive 2, and a standard 40 pin floppy crossover cable allows me to emulate a pair of drives. Now, I want to replace the RX50 drive on my Pro/380 with this setup to allow it to install POS. However it does not work, the Pro fails startup with an error on the floppy controller board, and so far it looks like POS can't see the disks. So what is the difference between an RX50 and a pair of 5.25 drives, and is it possible for Flashfloppy to emulate whatever oddness is in a true rx50? CZ
