8-Bit IDE controller pre-ordering poll

[IBMMuseum]

Yes, the MCA bus was used on all 386+ PS/2 machines. The entry models 25 & 30 (XT/AT) use the ISA slot. I don't expect problems with fitting the card is the slot, but rather with the IRQ setting.

To be more correct, the 8086-based versions of the PS/2 Model 25 and 30 have 8-bit expansion slots (2 and 3 respectively) like the IBM XT. "ISA" to me denotes a 16-bit card and slot like an IBM AT. There are 286-based versions of the Model 25 and 30 ("25 286", "30 286") and a 386SX version of the Model 25 ("25SX") with "ISA" slots (the 25SX has three 16-bit expansion slots, one is a "reversed" bracket designed for a special Ethernet or Token Ring network adapters).

There are other PS/2 models with 386SX, 386SLC, 486SLC2, and 486SLC3 CPUs ("386+"), but an ISA bus. Mike is right in saying there are several models (below the Model 50) that are not a microchannel bus. In this particular case (an 8-bit card on the Model 30) I don't think there will be an issue with an IRQ, unless it uses the same IRQ as a hard drive with one actually attached (the HDD controller is on the planar, but is deactivated if the proprietary HDD ins't connected).

 

[michal]

For those of you not following the thread, we're talking about an 8Bit, ISA, IDE controller to put into your PC/XT machines

To be more correct, the 8086-based versions of the PS/2 Model 25 and 30 have 8-bit expansion slots (2 and 3 respectively) like the IBM XT. "ISA" to me denotes a 16-bit card and slot like an IBM AT.

Well I've been following this thread's terminology and also mine, about the ISA slots. On the Wikipedia the terms 8-bit ISA and 16-bit ISA are used. Well I'm sure You're right about the PS/2 models :D

And back to the subject, if it's gonna work, then I'll take it !

 

[mbbrutman]

I think the correct terms are actually PC bus and ISA bus. 8 bit ISA and 16 bit ISA usually are descriptive enough to avoid any confusion.

 

[Mike Chambers]

oh wow awesome... i would buy probably two. definitely one. i voted one on the poll.

Q: how pwn is this?

A:VERY PWN!

 

[dpatten]

I'd certainly buy one for $25. I too am especially interested if it works in the 8086 based PS/2 model 30. The 20 MB Hard drive in mine is getting a bit full...

Is the $25 price for an assembled card, the price of a kit or just the bare pcb?

 

[hargle]

$25 may be little optimistic. I've had a quick slab of reality on PCB manufacturing costs sent to me lately. Some of the components are a bit expensive too, not to mention just the stupid metal bracket that attaches the thing to your case is going to cost about $1.50 each if I have to buy them online. (it's TOUGH to find anyone selling ISA slot brackets nowadays)

I'm actively seeking better priced components and lowest cost PCB manufacturing. I think I found an IC supplier right here on VCF, so we might be able to keep a majority of the project in-house, which is what I'd really like to do.

It may still be possible to swing a $25 price tag on a build-it-yourself kit (plus postage) or slightly more for an assembled+tested version. We really won't know until we're further along in the debugging cycle how many spins of the board we will have to pay for, nor do I know how long it'll take me to solder one of these cards up and then test it.

That said, I can see from the poll results that we're quickly reaching a milestone of about 100 cards, which means that the price will drop when buying parts in bulk, so that'll help out the costs all around, so maybe we are back to our ideal $25 price point.

Remember: this card is 100% open source (design, layout, schematic, BIOS, drivers, etc) and is dedicated to everyone here on VCF. Many, many hours of time have already been put into the project by andrew lynch and myself, and we'd really like people to buy these card based not on cost, but because it's a cool project and a labor of love and it may inspire others to build more new toys for our old friends. I'm going to keep the costs as low as possible without going negative, so we may not know the final price til we start rolling on the manufacturing front.

Hate to give a total non answer to your question, but we're still in the development cycle, so it's all going to be in flux for a little bit longer. I'm just trying to get an idea of how many people are interested so I can bulk purchase appropriately.

 

[IBMMuseum]

...I too am especially interested if it works in the 8086 based PS/2 model 30. The 20 MB Hard drive in mine is getting a bit full...

I know from experience that the sIDE adapter works on the 8086-based Model 30, as well as the Trantor T130B (SCSI). The 2Gb HDD I had on there (plus an external SCSI CD-ROM) only showed 1Gb for some reason, but that was a large enough space for me to work with. It is interesting that there is an IBM 30Mb proprietary drive that works on the 8086-based Model 25 (with a later BIOS than the comparable Model 30) but it won't work on the 8086-based Model 30 (there you are limited to the 20Mb version with the built-in interface).

 

[channelmaniac]

Hell,

As I scrap out old ISA cards, I can save all the brackets. Some will have holes for various DB connectors, but hey, can't beat the price.

Did you find a good price on PC board fabricating? I paid $2.50 a square inch plus a per order $10 fee to get my Colecovision A/V mod kit boards built.

RJ

 

[hargle]

PCBnet.com can do a run of 100 boards for ~$8 each, plus whatever shipping will cost. That was on a 3 week turnaround, and they are an overseas production house. I also had to guess on a few items when doing the online quote, as I have no idea of the hole count/hole size and a few of the other options are outside of my knowledge. That price may go up if I borked some of the options, and I've no idea what shipping from china might cost. I'd kinda estimated $10-13 each originally.

PCBFabExpress.com can do 50 boards in 10 days for ~$11 each. They didn't have as many options in their online quote form for slot fingers and stuff, so that value may change when the actual layout gets sent to them. They are at least in the USA.

If anyone else would like to try and find some quotes, please let me know and I'll get you whatever information I have about the board. This stuff is *way* out of my league.


As for the ISA slots, thank you for the offer! I would like to use identical parts though. If we're going so far as to custom make PCBs, might as well go that extra mile and use the same bracket on all the builds. Either that, or we drill a bunch of holes on the edge of the card to accommodate any kind of bracket, but that seems kludgey.

I absolutely want to order whatever ICs I can from you though. I sent you a PM with my contact info so we can discuss pricing offline. Once we get some per unit costs for the ICs in place, we can really start nailing down the target price point...

 

[frozenfire75i]

I did some searching in my inventory of hard drives, and came up with some 600MB and under 3.5” IDE Hard Drives. Here is what I have:
4X IBM 364MB 924C/16H/48S
5X Quantum Maverick 270MB 944C/14H/40S
8X Maxtor 540MB 1064C/16H/62S
How would those work with this 8-BIT IDE Card? Also what would be the best?

 

[hargle]

I did some searching in my inventory of hard drives, and came up with some 600MB and under 3.5” IDE Hard Drives. Here is what I have:
4X IBM 364MB 924C/16H/48S
5X Quantum Maverick 270MB 944C/14H/40S
8X Maxtor 540MB 1064C/16H/62S
How would those work with this 8-BIT IDE Card? Also what would be the best?

Any drive that supports LBA addressing (ATA-2, or built in 1994 or later) should work with the card. The BIOS currently has an upper size limit of 137G, but could be expanded to 144 petabytes(!) by adding 48Bit LBA support later on.

There is currently no support for CHS addressing in the BIOS. It could be added, but do we *really* need to use crusty old hard drives like that when perfectly good, modern, cheap, fast and quiet drives work even better?

IMO, the best drive to use is an 8-10G drive. DOS 6.22 supports 8.4G through a series of 2G partitions, and that's a LOT of playroom for an XT.
My test machine has a drive pulled from an xbox-1, and that's the drive I intend on using when I button the thing up.

 

[Unknown_K]

What OS are we going to be using on this card? There are limits on directories and partition sizes on the older DOS versions, and DOS 6.22 takes up quite a bit of memory on an XT doesn't it? Will older fdisk commands work on this card?

 

[per]

What OS are we going to be using on this card? There are limits on directories and partition sizes on the older DOS versions, and DOS 6.22 takes up quite a bit of memory on an XT doesn't it? Will older fdisk commands work on this card?

All operating systems supporting a hard drive, can use this card. But there are, as you say, limitations.

I don't know if it is possible or how smart it would have been to take a 100Gb disk and just make a coupple (say five) 10Mb PC-DOS 2.1 partions on it. that's 99.95% waste of disk space!

 

[hargle]

per is exactly correct.
You can use any OS you want. The drive support is built into the INT13 routines built into the card's BIOS. If your OS of choice includes support for FDISK, you are set. No drivers required at all. (there will be a driver required for CD-ROM support, provided I can get it to work on the existing hardware, but that's a different story)

There are however a number of limitations and variables as to how big a drive you can install, depending on which OS you choose.

For example, DOS 2.0 can only see a 10MB partition. You can probably have multiples of them though.

DOS 3.0-3.3 have support for 32MB partitions.

DOS 4.0-DOS 6.22 have FAT-16 support, and can thus use 2Gig partitions.

DOS 7 (windows 98SE) has FAT-32 support and can see 137Gig partitions.

DR-DOS and FreeDOS have different limits. (FreeDOS claims to be able to do 2TB partitions)

There's also the limits on how big a physical drive the OS can see. Most DOS versions will quit at 8.4Gig. DOS 7 can see 137Gig drives, because it is using enhanced INT 13 support.

Then roll in the fact that you can only have a maximum of 24 hard drive letters, C: through Z: on your machine. Then factor in that you may not be able to run all of these versions of DOS on an 8088 based CPU.

Essentially what I'm trying to say is that this card is not going to get in your way of doing anything you want to do. If you can't see the entire drive, it's not going to be this card's fault.

 

[Ole Juul]

hargle: "Then roll in the fact that you can only have a maximum of 24 hard drive letters, C: through Z: on your machine."

I use 25 and perhaps 26 are possible though likely undesirable. My main machine doesn't have a B: drive so I use that letter as a substitute drive. I don't know if DOS would allow a partition by that name since I haven't tried it. Sorry to pull things off topic a bit, but I thought that this was relevant here.

 

[per]

I use 25 and perhaps 26 are possible though likely undesirable. My main machine doesn't have a B: drive so I use that letter as a substitute drive. I don't know if DOS would allow a partition by that name since I haven't tried it. Sorry to pull things off topic a bit, but I thought that this was relevant here.

The standard DOS boot sector from version 2.x and later automaticly tell the initalizion code how many disk drives there are. Howeve, there is one exception, and that's if there is only one disk drive.

For some reason, only one disk drive is reported as two, I don't know why but it does. Any other number of floppy drives (2-4) get reported as the acutal value. Anyway, if FDD B: isn't present, a read/write to B: will trigger drive A: IIRC.

[COLOR="Gray"]Loaded:                      PUSH CS			; -
                             POP DS			; Make DS = CS[/COLOR]
[B]                             INT 011			; Equipment check
                             ROL AL,1			; -
                             ROL AL,1			; Rotate AL 2
                             AND AX,3			; Only one disk drive?
                             JNZ manyfdds		; Jump if not
                             INC AX
manyfdds:                    INC AX			; Number of floppy-disks, with the exeption as only one get reoprted as two[/I][/B]
                             MOV CX,AX			; Save in CX[/B]
[COLOR="gray"]                             TEST B[07C1E],80		; Is bit 7 of ??? set?
                             JNZ KeepAX			; Keep AX if not
                             XOR AX,AX			; Clear AX
KeepAX:                      MOV BX,W[Status]		; ???Get status
                             JMP 0070:0000		; Run loaded code[/COLOR]

I don't think DOS 1.0 behaves this way.

 

[dpatten]

$25 may be little optimistic.

<snip>

Hate to give a total non answer to your question, but we're still in the development cycle, so it's all going to be in flux for a little bit longer. I'm just trying to get an idea of how many people are interested so I can bulk purchase appropriately.

Any update on bulk purchases? I'd be more than happy to pre-pay if it was able to help you offset the cost. Tho I might have a time swinging $50 with "she who wields the purse-strings"

 

[gerrydoire]

Small WORKING laptop drives are very hard to find, there are still plenty of smaller IDE desktop drives around.

I agree.

The best bet for 8-Bit IDE is still CF CARDS.

CF Cards are plentyful and cheap for the most part.

 

[gerrydoire]

All operating systems supporting a hard drive, can use this card. But there are, as you say, limitations.

I don't know if it is possible or how smart it would have been to take a 100Gb disk and just make a coupple (say five) 10Mb PC-DOS 2.1 partions on it. that's 99.95% waste of disk space!

2 Gig CF Card more than enough for an XT.

 

[StickByDos]

Put me down for 2, possibly kit, as long as there is not many small cms chips