MDS Single Density Floppy Interface (CDC) and possubly channel Board on eBay.com

[Vale, Martyn]

 

Hi All,

 

There’s a listing on eBay.com item number 205109638823 for a “Vintage Rare Retro Intel Multibus MDS Double Density Floppy Drive Controller CDC”

 

It is however a Single Density Controller which looks to be in good condition.

 

Possibly the Channel Board from the same seller under item number 205109643837 for a “Vintage Rare Intel Multibus MDS Floppy Drive Controller Channel PWA 1000467 75'”

 

The issue with this is there are no firmware roms although these are on Bitsavers and one of the Bit Slice Processor set is missing as well.

 

Bye

Martyn.

 

 

[scott baker]

Hello Martyn,

I've been looking to build myself an ISIS-II compatible system, but one of the things that has left me a little bit confused is the floppy controller that is necessary for ISIS-II. Is this pair of boards the right set? I *think* what I'm looking for is an SBC-201 set which would include both a channel board an an interface board.

Scott

[Vale, Martyn]

 

Hi Scott,

 

You could use the SBC-201 board set, however this is single density and fairly rare these days. Most of the software images are for SBC-202 Double Density set and this is what I would recommend.

 

For some pointers see Bill’s excellent write up here:

 

https://www.nj7p.info/Computers/Multibus/Restoration/CaseStudy-MDS_225.html

 

Bill is actually using a single board Zendex controller here, but the SBC-202 set will be fine.

 

If you need specific part numbers etc let me know.

 

There’s a fair bit of info on my Youtube Channel if you are interested “Martyn's Vintage Computing”

 

Thanks

Martyn.

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[roger arrick]

Scott, Martin

There are 2 possible Floppy drive controller board sets for MDS8xx and MDSII systems - the 201 set which is single density and 202 set which is double density

There are 2 boards in a set - one is the interface board and one is called the channel board.
The interface boards look different, lots of analog.
The channel boards are the same  but their ROMS are different.

Single density FD channel board, Intel PWA 1000467 same as DD except ROMSs

Single density FD Interface board, Intel PWA 1000603

Double density FD channel board, Intel PWA 1000467 but different ROMs than SD.

Double density FD interface, Intel PWA 1001036

And of course the cabling which is a hassle.

Some other options are:
Zendex ZX-200A Floppy Controller replaces  SBC-201 (88H) AND SBC-202 (78H)

Zendex ZX-203 Floppy Controller replaces SBC-201, 202, 206.

National Semiconductor BLC-8201 replaces SBC-201

--  Roger Arrick -- Tyler, Texas, USA -- Ro...@Arrick.com --

---

From: intel-...@googlegroups.com <intel-...@googlegroups.com> on behalf of scott baker <smb...@gmail.com>
Sent: Saturday, November 30, 2024 11:35 AM

To: intel-devsys <intel-...@googlegroups.com>
Subject: intel-devsys Re: MDS Single Density Floppy Interface (CDC) and possubly channel Board on eBay.com

--

[William Beech]

Guys,

205109638823 is the interface board for the dual density MMFM SBC-202.  205109643837 is the controller board for the MFM SBC-201.  I don't believe they would work together.  ANd Intel 3XXX logic is hard to find!

If you are interested in building a controller may I recommend the Zendex ZX-200A smart controller board.  It is a single card using an Intel 8085 processor. 

I have added all the Zendex Manuals I hold to the Zendex folder on the Intel_Devel google drive.  I have working ZX-200 boards here in my MDS systems.

Let me know if I can help!

Bill

--

[scott baker]

I've been studying up on controllers and have a couple of questions.

First, I think I finally understand that Series II came with two different kinds of controllers:

1) The built in controller on the IOC board. This was for a 5.25" disk of ~ 250K capacity

2) The SBC-201/SBC-202 2-board controller sets. There were for external 8" disks of ~ 250K (SD) or ~ 500K (DD) capacity.

My questions are mostly around (1) the controller built into the IOC. Looking at the design, it would be easier for me to emulate this than emulating (2) since the IOC seems to have a simple parallel buffer between the primary processor and the IOC processor. The SBC-201 channel board, on the other hand, relies on bus mastering as well as a series of IO ports between the two processors. However, I don't yet understand the disk format of the 5.25" 250K disks -- is it compatible with the 8" disk images? From what I've been able to determine, the 8" images are 26 sectors per track, 77 tracks, 128 bytes per sector. I haven't been able to find specs on the 5.25" disk format anywhere.

Thanks,

Scott

[mark.p...@btinternet.com]

Scott

ISIS I through ISIS III support 8” disks and ISIS PDS supports  5 ¼” disks. The physical layout formats are documented in

https://mark-ogden.uk/idkstool.html#interleave

Single Density 8” disks have 26x128 FM sectors per track

Double Density 8” disks have cylinder 0 as 26x128 FM Sectors the rest are 52x128 FM sectors per track

Both have 77 tracks and are single sided

The ISIS Directory is located at Cylinder 1 sector 1

 

Note ISIS III could also support NDS-II which allowed remotely mounted files and a hierarchical file structure

 

5 ¼” disk for the PDS have cylinder 0, head 0 as 16x128 FM sectors, the rest are16x256 MFM sectors. In total there are 40 cylinders and the disk is double sided.

The ISIS-PDS directory is located at Cylinder 39, head 0, sector 1

 

Note iPDS also supports bubble memory!!

See pages 8-88 onwards in https://mark-ogden.uk/files/intel/publications/162606-004%20iPDS%20Personal%20Development%20System%20Users%20Guide-Oct83.pdf

 

Note the layout of ISIS files can be found elsewhere, but if you need to create new disks my mkidsk utility can create imd or img disk images with the correct layout for ISIS I through ISIS III and ISIS PDS, however because the IMD format supports only FM or MFM encoding, M2FM is recorded as MFM.

 

ISIS IV effectively uses iRMX disk format, the specific format should be read off the disk header.

The format is documented in https://mark-ogden.uk/files/intel/publications/143308-001%20Structure%20of%20iRMX%2086%20Named%20File%20Volumes-Jan81.pdf. Note ISIS IV uses a 128 byte fnode size, unlike most iRMX disks which use 90 bytes. This is reflected in the header.

 

Mark

To view this discussion visit https://groups.google.com/d/msgid/intel-devsys/686fa3f4-d7aa-44ca-99e2-396380a6c9afn%40googlegroups.com.

[scott baker]

Yeah, I have a PDS and I have an SBX-251 for it, and it boots from bubble. :) I couldn't find a multimodule adapter board for my iPDS so I build one myself (https://www.smbaker.com/adding-bubble-memory-to-an-ipds-100-personal-development-system-clonding-the-ipds-120-multimodule-adapter -- gerbers of the multimodule board are up in case anyone else needs one). This is what led me down my path to start exploring multibus. There's only so many home built boards you can cram inside a PDS -- basically a couple of multimodules.

So the Series II Model 225, with a single 250K drive connected to the IOC, is an 8" drive? I'm not sure why I thought it was 5.25". Checking the literature this morning I can't see anything that should have led me to believe that. Maybe I just assumed internal disk == physically small disk. I guess this is what happens to someone like me who has never actually seen one in person. :)

So then in theory I could clone the IOC and boot any of the ISIS SD disks in the IOC. It'd be a pretty tight environment, though.

Thanks for the clarification, Mark, it's a big help.

Scott

[William Beech]

Scott et al,

I also have a iPDS but without bubble memory.  And an MDS-800 and MDS-II IPC (MDS-225) both built from the cards.

The IOC uses a controller for IBM 3740 format SSSD FM diskettes. I have an IOC board but it is not used in the system. Yes, the IOC disk is an 8-inch disk on the original system.  On my MDS-800 and MDS-225 systems I am using 1.44 MB 3.5-inch FDC's. 

Nice page on the multimodule adapter.  Did you find a source of real multimodule connectors?  I could sure use a few sets!

You might check out my web pages - www.nj7p.org and www.nj7p.info.  I have a lot of information on there and some duplicate tools to those developed by Mark. 

I live in Hereford, AZ., near Fort Huachuca, where I worked as a Computer Engineer (Graduate of U of A - 1988) as my second career.

Bill

To view this discussion visit https://groups.google.com/d/msgid/intel-devsys/a0617c13-de58-46bc-a5b8-4acbedc52717n%40googlegroups.com.

[scott baker]

No luck on a source for multimodule connectors. I've been using standard 2x18 headers on my own boards and on my multimodule adapter. I'd much rather have the "real" ones, but as far as I can tell they're unobtainable. I did send emails to a few places that claimed to have some stock, but those sources usually either 1) do not have an accurate inventory and are claiming to have stock they don't really have, or 2) if they do have a part they charge between 10X and 100X what the reasonable cost for the part is.

I have thought about cloning the SBX-251, though it still leaves the issue of scavenging bubble memories and chipsets from somewhere. Fortunately I was able to get myself an SBX-251 for a reasonable price and didn't have to clone it. But not everyone else is so lucky.

I'm also a U of A graduate. :)

Scott

[William Beech]

Mark,

I am trying to clean up my Intel code builds.  I am having a problem
that I believe we addressed long ago in ASM80.  On a good assembly, it
returns 1 rather than 0, which my scripts is expecting.  I suspect I am
back using an old version of the Intel ASM80.

Thanks!

Bill

[William Beech]

Mark,

If this is normal behavior for Intel ASM80, I can just modify the script
to expect a 1 for normal completion.

Bill

[mark.p...@btinternet.com]

Bill

Are you using the c port or asm80 under Thames

Mark

Regards

Mark Ogden

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From: intel-...@googlegroups.com <intel-...@googlegroups.com> on behalf of William Beech <nj...@nj7p.info>
Sent: Monday, December 9, 2024 7:35:00 PM
To: intel-...@googlegroups.com <intel-...@googlegroups.com>
Subject: Re: intel-devsys ASM80

 

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[mark.p...@btinternet.com]

Bill

Although I have recently done a minor modification to the c-port of asm80 to add a new option ISISNAME to force names to limit to 6 characters, the previous change was in 14-Feb-2024 and that has been on github for sometime. Both versions work correctly in terms of return code i.e. 0 for success.

 

If you are using the c port run asm80 -V which should tell you the version you are using. The latest on github is 2024.2.14.22.

 

Regards

Mark

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[William Beech]

Mark,

Here are results I get:

C:\Users\nj7p>d:\bin\asm80 -V

FILE ERROR, -V

C:\Users\nj7p>d:\bin\asm80 -v

FILE ERROR, -v

C:\Users\nj7p>

I suspect I am using the Thames version.  I just grabbed your latest off GitHub.  I will clear this up on my end and continue my Web update.

Thanks!

Bill

To view this discussion visit https://groups.google.com/d/msgid/intel-devsys/006201db4a80%244b213b60%24e163b220%24%40btinternet.com.

[mark.p...@btinternet.com]

Bill

You are using a very old version of the C port of ASM80.

The latest can be found by cloning the c-ports repository.

You are missing many enhancements including

1. Support for full Windows names, both as input files and include files
2. Support for up to 31 character label names and the $ name separator supported by PL/M-80, underbar is also supported
3. No external temporary files
4. Support for larger and more complex programs
5. Date support in the title for listings
6. Long line support, including command line

 

The other tools have also been significantly enhanced i.e. PL/M-80, LINK, LOCATE, LIB, IXREF all of which support the longer Windows filenames

Regards

Mark

To view this discussion visit https://groups.google.com/d/msgid/intel-devsys/d817de5f-e93e-451b-acac-a7838c772a3e%40nj7p.info.

[William Beech]

Mark,

I have the latest cports from GitHub.  When I try to build on vs2022, all the sources fail with "getVersion.cmd -w :VCEnd" exited with code 1.  Any idea what I did wrong?

Bill

To view this discussion visit https://groups.google.com/d/msgid/intel-devsys/008b01db4a8d%24f6a193b0%24e3e4bb10%24%40btinternet.com.

[mark.p...@btinternet.com]

Bill

I have been unable to reproduce your problem with a cloned copy direct of the c-tools repository from GitHub

I have however uploaded the latest versions to GitHub. This no longer uses the Batch file scripts but compiled C code, which is slightly faster.

See if this helps, if it doesn’t I will share pre-compiled versions of the code for you to use

To view this discussion visit https://groups.google.com/d/msgid/intel-devsys/6be8d247-e58f-4563-83c8-fe43ec79cfed%40nj7p.info.

[andre...@gmail.com]

Scott—

 

For the 36 pin male version, other than the intel PN 103109-001, I have a viking PN 292-0001.  Do you have other manufacturers and part numbers?

 

I haven’t built your multimodule adapter for my iPDS yet, but when I get around to it the SBX-251s clone would be nice to have also.  I have one or two SBX-251 but am using them elsewhere.  I have a surplus of bubbles and support chips so am well set there.

 

Thanks

craig

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[William Beech]

Mark,

Here is a screen shot of what I get.

Bill

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[William Beech]

Mark,

Further digging into the "output" file gives the following for the compile of ASM80 (and all the others):

17>Get Version (asm80 - Debug)
17>'D:\Development\0Github\New' is not recognized as an internal or external command,
17>operable program or batch file.
17>C:\Program Files\Microsoft Visual Studio\2022\Community\MSBuild\Microsoft\VC\v170\Microsoft.CppCommon.targets(156,5): error MSB3073: The command "D:\Development\0Github\New Stuff\c-ports-main\Tools\getVersion.exe -w
17>C:\Program Files\Microsoft Visual Studio\2022\Community\MSBuild\Microsoft\VC\v170\Microsoft.CppCommon.targets(156,5): error MSB3073: :VCEnd" exited with code 9009.
17>Done building project "asm80.vcxproj" -- FAILED.

I don't understand this except there is a missing command "New" and getVersion.exe is failing.

Bill

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[William Beech]

Mark,

As a test, I have tried to build a project under VS2008.  When I try to build it, I get:

1>------ Build started: Project: asm80, Configuration: Debug Win32 ------
1>Compiling...
1>cl : Command line warning D9035 : option 'Wp64' has been deprecated and will be removed in a future release
1>asm1m.c
1>d:\development\0github\new stuff\c-ports-main\asm80\asm80.h(11) : fatal error C1083: Cannot open include file: 'stdbool.h': No such file or directory
1>asm2m.c
1>d:\development\0github\new stuff\c-ports-main\asm80\asm80.h(11) : fatal error C1083: Cannot open include file: 'stdbool.h': No such file or directory
1>asm3m.c
1>d:\development\0github\new stuff\c-ports-main\asm80\asm80.h(11) : fatal error C1083: Cannot open include file: 'stdbool.h': No such file or directory
1>asm4m.c
1>d:\development\0github\new stuff\c-ports-main\asm80\asm80.h(11) : fatal error C1083: Cannot open include file: 'stdbool.h': No such file or directory
1>asm5m.c
1>d:\development\0github\new stuff\c-ports-main\asm80\asm80.h(11) : fatal error C1083: Cannot open include file: 'stdbool.h': No such file or directory
1>asm6m.c
1>d:\development\0github\new stuff\c-ports-main\asm80\asm80.h(11) : fatal error C1083: Cannot open include file: 'stdbool.h': No such file or directory
1>asm8m.c
1>d:\development\0github\new stuff\c-ports-main\asm80\asm80.h(11) : fatal error C1083: Cannot open include file: 'stdbool.h': No such file or directory
1>asxref.c
1>d:\development\0github\new stuff\c-ports-main\asm80\asm80.h(11) : fatal error C1083: Cannot open include file: 'stdbool.h': No such file or directory
1>cntrlm.c
1>d:\development\0github\new stuff\c-ports-main\shared\os.h(10) : fatal error C1083: Cannot open include file: 'stdint.h': No such file or directory
1>debug.c
1>d:\development\0github\new stuff\c-ports-main\asm80\asm80.h(11) : fatal error C1083: Cannot open include file: 'stdbool.h': No such file or directory
1>emitm.c
1>d:\development\0github\new stuff\c-ports-main\asm80\asm80.h(11) : fatal error C1083: Cannot open include file: 'stdbool.h': No such file or directory
1>globlm.c
1>d:\development\0github\new stuff\c-ports-main\asm80\asm80.h(11) : fatal error C1083: Cannot open include file: 'stdbool.h': No such file or directory
1>initm.c
1>d:\development\0github\new stuff\c-ports-main\asm80\asm80.h(11) : fatal error C1083: Cannot open include file: 'stdbool.h': No such file or directory
1>io.c
1>d:\development\0github\new stuff\c-ports-main\asm80\io.c(14) : fatal error C1083: Cannot open include file: 'showVersion.h': No such file or directory
1>listm.c
1>d:\development\0github\new stuff\c-ports-main\asm80\asm80.h(11) : fatal error C1083: Cannot open include file: 'stdbool.h': No such file or directory
1>memory.c
1>d:\development\0github\new stuff\c-ports-main\asm80\asm80.h(11) : fatal error C1083: Cannot open include file: 'stdbool.h': No such file or directory
1>nkeym.c
1>d:\development\0github\new stuff\c-ports-main\asm80\asm80.h(11) : fatal error C1083: Cannot open include file: 'stdbool.h': No such file or directory
1>rdsrc.c
1>d:\development\0github\new stuff\c-ports-main\asm80\asm80.h(11) : fatal error C1083: Cannot open include file: 'stdbool.h': No such file or directory
1>startm.c
1>d:\development\0github\new stuff\c-ports-main\asm80\asm80.h(11) : fatal error C1083: Cannot open include file: 'stdbool.h': No such file or directory
1>Generating Code...
1>Build log was saved at "file://d:\Development\0Github\New Stuff\c-ports-main\asm80\Debug\BuildLog.htm"
1>asm80 - 19 error(s), 1 warning(s)
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

I don't find those header files anywhere in your source for c-ports- main.  I have downloaded the latest c-ports-main as a zip file from your GitHub repository.  Are they an addition you made to your VS2022?  Are the files I am missing from the VS2022 involved in your GetVersion code?  I am trying to figure out what I am missing on this end.  I should be able to pull down your code and just have it build.  But that never seems to work on my end.

Bill 

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[mark.p...@btinternet.com]

Bill

The build will not work with VS2008 as it doesn’t support the C standard I use, which is C17 (i.e. 2017 which is 9 years after VS2008 was released). In practice the code would probably compile using C11 but again this 3 years after VS2008.

 

stdbool.h  is a standard C header that declares type bool, true and false. The other C standard features I use include stdint.h, and _Noreturn neither of which are supported in the old C standard used by VS2008

 

 

From your other emails I looked at the error messages and screen. It looks like the space between New and Stuff is the problem. In the solution file I hadn’t put quotes around the path to the executable and the shell that invokes the code appears to have failed as it thinks the application name is New!!!

I will update my solution file to address this, but for now simply renaming “New Stuff” to remove the space should hopefully solve the problem.

 

As noted before, it is probably better to clone the repository which will include the git history, rather than download the ZIP file. After the initial clone  updates can be done with git pull.

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[William Beech]

Mark,

I understand that.  I figured it out when running down stdbool.h and stdint.h.  So I must use VS2022 for the build.

I changed "New Stuff" to "New_Stuff" and used vs2022,  c-ports-main all compiled with NO errors.  I did not figure the griping about New was from the path!  Thanks you for pointing it out.

I need to figure out Git.  I have always just pulled down the ZIP file from GitHub.  I need to learn to use the tools! 

I knew it was something I was doing that caused the incompatibility.  I just did not know where.

Thanks again!

Bill

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