Industrial passive backplane can be more than 10 slots even more. Needs a SBC board to go with it. Very specialized as these cannot cover interrupts and DMA across so many slots, so this is done with addresses and polling methods to interface with specialized i/o interface to run motions and read back from sensors.

Cheers,

pentiumspeed wrote on 2023-07-30, 18:22:

Industrial passive backplane can be more than 10 slots even more. Needs a SBC board to go with it. Very specialized as these cannot cover interrupts and DMA across so many slots, so this is done with addresses and polling methods to interface with specialized i/o interface to run motions and read back from sensors.

Cheers,

Correct, and I mentioned that in the OP.

What I'm interested in are computers besides industrial setups that have more than the typical 8 slots.

Shponglefan wrote on 2023-07-30, 14:29:

In doing some further research, apparently there are some models of Laser-brand computers (Laser 386VT and 486 tower systems) that featured 10 ISA slots (8x 16 bit and 2x 8 bit). While there are images of the motherboard layouts on The Retro Web, I can't find pictures of the actual cases for these computers.

Not period correct, but my Little Devil case supports boards with up to 10 slots. Not particularly cost effective though, the PC-V8 costs almost 500€, and the PC-V10 is a smidgeon over 500. And for my V8, I had to remove the drawer from the desk I put it under, those cases are MASSIVE.

I don't know any period correct case at any price that supports the same number of expansion slots/cards. At the right price, I'd love one 😀

Guessing the intent, several of IBM's mid-tower PS/1 models feature eight, 16-bit ISA slots, and, unlike lesser-integrated systems, they can all be populated with sound cards.

Cloudschatze wrote on 2023-07-30, 19:25:

Guessing the intent, several of IBM's mid-tower PS/1 models feature eight, 16-bit ISA slots, and, unlike lesser-integrated systems, they can all be populated with sound cards.

Why would anyone want 8 sound cards? I can understand 2 or 3 for maximum compatibility with games, but 8? Maybe it's my hearing impediment that makes this sound extreme, deaf in one ear and tone deaf in the other, so I can't tell the difference between a lot of cards. I do appreciate music from the 60s to 80s though 😀

AT&T 6386E WGS had 10 ISA slots, https://theretroweb.com/motherboards/s/atandt … -wgs-fm-0589-10
what the case looked like: http://www.bitsavers.org/pdf/att/6386_wgs/638 … GS_Brochure.pdf and
https://www.manualslib.com/manual/2182612/AtA … ?page=61#manual
The AST CUPID tower also had 10.... no pictures found yet

debs3759 wrote on 2023-07-30, 19:39:

Cloudschatze wrote on 2023-07-30, 19:25:

Guessing the intent, several of IBM's mid-tower PS/1 models feature eight, 16-bit ISA slots, and, unlike lesser-integrated systems, they can all be populated with sound cards.

Why would anyone want 8 sound cards?

Speaking for myself, compatibility and variety would be the pretense, but the real reason would be that it's excessive, ridiculous, and has the potential to be fun. 😀

Here's how I've considered populating an eight-slot PS/1:

• Creative Sound Blaster AWE32 w/WaveBlaster DB
• Gravis Ultrasound PnP
• Mediatrix Audiotrix Pro
• Media Vision Pro Audio Spectrum 16XL w/Korg Pro Wave DB
• Roland LAPC-I
• Roland SCC-1
• Yamaha/IBM Music Feature Card
• Yamaha SW60XG
  
  Creative Sound Blaster AWE32
  BASE : 0x220
  IRQ : 5
  DMA : 1, 5
  ADL : 0x388
  MPU : 0x330
  MPUIRQ : 5
  JOY : Disabled
  E8K : 0x620
  
  Gravis Ultrasound PnP
  BASE : 0x240
  CODEC : 0x34c
  IRQ : 3
  DMA : 7
  ADL : Disabled
  MPU : Disabled
  MPUIRQ : N/A
  JOY : 0x201
  
  ("Gravis MIDI" support available via MEGA-EM and UltraMid.)
  
  Mediatrix AudioTrix Pro
  WAVE : 0x530
  IRQ : 10
  DMA : 3
  ADL : 0x388
  MPU : 0x370
  MPUIRQ : N/A
  EFFECTS: 0x318
  JOY : Disabled
  
  Media Vision Pro Audio Studio 16XL
  BASE : 0x388
  IRQ : 7
  DMA : 6
  ADL : 0x388
  MPU : 0x300
  MPUIRQ : 2/9
  JOY : Disabled
  
  (Allows for 16-bit "PAS" playback support in this configuration.)
  
  Roland LAPC-I
  MPU : 0x332
  IRQ : 2/9
  
  Roland SCC-1
  MPU : 0x334
  IRQ : 2/9
  
  Yamaha/IBM Music Feature Card
  MPU : 0x2a20
  IRQ : 4
  
  Yamaha SW60XG
  MPU : 0x310

Tee hee - now that's an answer 😜

(I'd choose different cards - SSI-2001 replicas etc - but can easily imagine similar setups)

On-topic:
Max number of ISA slots I ever saw in a non-backplane system was on the Soyo SY-020A motherboard: 12 in total, 10 16b, 2 8b. ALR also had a range of systems with 10 slots - iirc 'Cupid' - although they could have been EISA. Still, EISA slots support ISA cards too 😉

Keep in mind consumer level (including gamers') are rarely above 8, most commonly 6 slots. The extended number of slots more than 8 are firmly in the SBC and server level, I have not seen any workstations that have more than that and yes, I searched lots over the years.

Originally early ATX specifies 8 slots and might be still is but most usually see are 6 to 5 slots for full ATX.

PC XT started at 8 slots but the first slot is reserved for special card.

AT, 386 and 486 Clones usually are to be at 8 but many cost cutting is less.

IBM did produce large number of MCA slots but this is usually for server.

But! Compaq at one time did make large number of 8 EISA slots in Proliant 4500. Up to 4 processor cards and for memory; 8 on board, on expansion board of another 8 memory slots in a Very large rack mount.

Intel Xtended xPress board, which I happen to have the board set. If you only use one processor card, you can theoretically can use 9 slots of PCI and EISA/ISA.

Cheers,

dionb wrote on 2023-07-30, 21:36:

Max number of ISA slots I ever saw in a non-backplane system was on the Soyo SY-020A motherboard: 12 in total, 10 16b, 2 8b. ALR also had a range of systems with 10 slots - iirc 'Cupid' - although they could have been EISA. Still, EISA slots support ISA cards too 😉

Wow forgot about that Soyo board, it is probably the king leader for ISA slots !!! Yeah ALR did make a hand full of boards with 10. The AST Cupid came in two variants: ISA only and EISA+ISA, both with 10.
As far as cases for them is a hard to find..

Hi, I think that 286 and 386 mainboards have a chance for having the most "ISA" slots.
Simply because they used to be physically huge (late 80s models).
And because they relied on expansion cards (little on-board devices, if at all)..
The discreet nature of the support chips (no chipsets or early chipsets) also made the bus drivers electrically stronger, maybe.
So they could handle a higher bus load/capacity.

Anyway, it's possible to extend ISA. It's a real parallel bus, unlike PCI.
So it's possible to attach a second backplane to one of the ISA slots.
Merely the power supply and bus noise must be taken care of.

Cloudschatze wrote on 2023-07-30, 19:25:

Guessing the intent, several of IBM's mid-tower PS/1 models feature eight, 16-bit ISA slots, and, unlike lesser-integrated systems, they can all be populated with sound cards.

You guessed correctly. 😉

And that's good to know about the IBMs. I'd been looking at similar system ever since I'd seen your MIDI General build with the Dell. Didn't know about the IBMs though. Eight 16-bit ISA slots would be pretty sweet for such a build.

debs3759 wrote on 2023-07-30, 19:39:

Why would anyone want 8 sound cards? I can understand 2 or 3 for maximum compatibility with games, but 8?

As someone who is moderately obsessed with computer audio from the 80s and 90s, I'd build a system with 12 sound cards if I could. 😁

dionb wrote on 2023-07-30, 21:36:

Max number of ISA slots I ever saw in a non-backplane system was on the Soyo SY-020A motherboard: 12 in total, 10 16b, 2 8b. ALR also had a range of systems with 10 slots - iirc 'Cupid' - although they could have been EISA. Still, EISA slots support ISA cards too 😉

Twelve slots! That's an impressive looking board.

I wonder what sort of case would have supported that. It's surprisingly difficult to find pictures of such cases...

Shponglefan wrote on 2023-07-31, 16:01:

[...]

Twelve slots! That's an impressive looking board.

I wonder what sort of case would have supported that. It's surprisingly difficult to find pictures of such cases...

A big sort...

These boards are rare, cases for them equally so. The Soyo SY-020A is a pretty standard full AT board below the keyboard connector. Above it, it's standard too, so would fit in a full AT case, except for those four extra 16b ISA slots up there. Would be perfect for fully internal cards.