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XT-FDC project level of interest

NobodyIsHere

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This poll is to measure if and how much interest there is on vintage-computer.com for an XT-FDC project. The poll only has an affirmative response since the default (no response) or negative reply don't matter in this case.

The XT-FDC is an 8 bit ISA board based on the National Semiconductor PC8477B that supports up to four floppy disk drives. It would support up to four floppy drives internally with an optional external connector for two. It will have an on board BIOS (written by Chuck so you know that's good) and configurable IO port, interrupts, and DMA.

It would have the same parameters as the XT-IDE project in terms of size, cost, availability, etc. Attached is a notional picture of the current design

View attachment 10147

Since I seem to have screwed up the poll option in this message please just "reply" to this thread with your vote.

Thanks and have a nice day!

Andrew Lynch
 
Last edited:

NobodyIsHere

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Hi
Actually this is a better question for Chuck but yes it does support HD drives. I think it even supports the ED media (2.88 MB) and high speed tapes according to the data sheet. As to whether it will support the XT-IDE style boot menu I don't know. Chuck is writing the BIOS so I suppose we'd get whatever user interface it has. I think it would be changeable like the XT-IDE BIOS is too.

Thanks and have a nice day!

Andrew Lynch
 

lucasdaytona

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it does support HD drives.

Definitely yes to this card!
It would be impossible to combine the XT-IDE with XT-FDC in a 8 bit bus? Would be nice, but since XT systems have a lot of slots, there's no need for this. I would love to use a XT-IDE, a XT-FDC, and a XT-OPL2 into the same system, that would be awesome!
 

NobodyIsHere

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Definitely yes to this card!
It would be impossible to combine the XT-IDE with XT-FDC in a 8 bit bus? Would be nice, but since XT systems have a lot of slots, there's no need for this. I would love to use a XT-IDE, a XT-FDC, and a XT-OPL2 into the same system, that would be awesome!

Hi
That's a neat idea but I wouldn't want to mess up the XT-IDE by combining it with a floppy controller. I guess I've adopted John Monahan's philosophy of one function per board. It makes for a much simpler design and a *lot* easier to debug. Also I think there would less interest in a combination board rather than a single function boards.

Thanks and have a nice day!

Andrew Lynch
 

NobodyIsHere

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Hi
Based on discussions with Chuck that is more of a BIOS software issue but yes it could support changing the boot drive.

Thanks and have a nice day!

Andrew Lynch
 

lucasdaytona

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Would the card have an easy way of changing the boot drive?

I think that this could be done using that pearce_jj option board, but it's nice to have this on a floppy controller. I can't stop thinking into a memory board projected by Andrew, one that uses any cheap big ram chip. But one problem at a time! Nice controller project.
 

Crypticalcode0

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Andrew I agree with that design practice unless and this is the only exception to that rule of thumb.
When for better or for worse features require the same hardware with minor modification, so that is inline with adding a Diode or a cap or even a resistor.

And besides that OPL3 is hardware compatible with OPL2 and where are we gonna find those chips?
 

NobodyIsHere

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I think that this could be done using that pearce_jj option board, but it's nice to have this on a floppy controller. I can't stop thinking into a memory board projected by Andrew, one that uses any cheap big ram chip. But one problem at a time! Nice controller project.

Hi
Yes, the XT-IDE V2 universal BIOS supports booting from a menu of available drives. I imagine this board could too but the intent is that the XT-FDC is a stand-alone independent project and does not rely on XT-IDE V2, XT-CF, or other boot menu BIOS board projects. You could use the XT-FDC in a PC by itself.

Thanks and have a nice day!

Andrew Lynch
 

NobodyIsHere

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Andrew I agree with that design practice unless and this is the only exception to that rule of thumb.
When for better or for worse features require the same hardware with minor modification, so that is inline with adding a Diode or a cap or even a resistor.

And besides that OPL3 is hardware compatible with OPL2 and where are we gonna find those chips?

Hi

I have no issue with restarting/reviving the ISA OPL2 project. Per did a lot of work and it is a shame the project just trailed off into nothingness. I suspect there will be a revival of it once the supply of commercial sound generator boards (you know who you are) diminishes. However that's another topic and there is another thread for it here:

http://www.vintage-computer.com/vcforum/showthread.php?23271-8-BIT-OPL2-Sound-board

The project is hung up on getting a set of prototype boards which is a common failure mode for community projects of this nature. I guess you win some and and you lose some. It could be restarted in an instant though if someone(s) were to "cut a check"

Thanks and have a nice day!

Andrew Lynch

PS, obtaining a YM3812 (OPL2) is not an issue IMO. There are several ways to get them such as vendors or reusing scrap chips (preferred method)

http://www.utsource.net/YM3812.html
 

pearce_jj

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BTW re ROM, is there a preference for the chip type? The SST39SFxx chips are very cheap and readily available, compared to 28C series EEPROM.
 

deathshadow

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8 bit Cards that support the higher throughput needed for high density or even ED drives are rare as hens teeth -- hell yeah, I'm all for supporting this one.

Particularly if it can be made to work in a Tandy 1000 SX.
 

NobodyIsHere

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BTW re ROM, is there a preference for the chip type? The SST39SFxx chips are very cheap and readily available, compared to 28C series EEPROM.

Hi

Sorry, I am not understanding. The 28C64 are common inexpensive 8KB devices

http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_74827_-1

The SST39Fxx chips are fine devices but seem like massive overkill for this simple project. Chuck only needs 4-8KB for the BIOS. The prices seems roughly equivalent too. Maybe this is a regional thing?

http://www.digikey.com/product-detail/en/SST39SF010A-70-4C-PHE/SST39SF010A-70-4C-PHE-ND/2297826

Personally, I wouldn't bother with either of those chips though and just burn an 2764 EPROM. They are so cheap as to be disposable and ubiquitous. Heck, pick them out of the garbage! They'll work fine and are almost indestructable.

Thanks and have a nice day!

Andrew Lynch

PS, lets see what Chuck thinks on the topic. I can change the design easily enough that I don't feel passionate one way or the other. They are both cheap parts.
 

NobodyIsHere

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8 bit Cards that support the higher throughput needed for high density or even ED drives are rare as hens teeth -- hell yeah, I'm all for supporting this one.

Particularly if it can be made to work in a Tandy 1000 SX.

Hi

Well if you want to thank someone (or blame someone) then dpatten "lit the fuse". Its about three messages down the list or so.

http://www.vintage-computer.com/vcforum/showthread.php?32423-Heads-up-Compaticard-I-on-eBay

He is right though. This is an opportunity for a community project like XT-IDE if we can get our act together.

Thanks and have a nice day!

Andrew Lynch
 

NobodyIsHere

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8 bit Cards that support the higher throughput needed for high density or even ED drives are rare as hens teeth -- hell yeah, I'm all for supporting this one.

Particularly if it can be made to work in a Tandy 1000 SX.

Hi
If compatibility with the Tandy 1000 SX is a priority then you'll have to personally participate in the prototype build and test phase. Otherwise there would be no compatibility testing or debugging done. I don't have a Tandy 1000 SX computer and Chuck probably doesn't either. Thus the need for community involvement!

Thanks and have a nice day!

Andrew Lynch
 
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