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Promdisk V Disk Emulator 8-Bit ISA

gerrydoire

Veteran Member
Joined
Aug 25, 2008
Messages
1,145
Something I recently acquired...

vdisk.jpg



PROMDISK VI is a high-performance, solid-state disk emulator board for ISA compatible computers. The PROMDISK VI board emulates a fixed disk drive with capacities ranging in size from 4MB to 128MB using on-board non-volatile NAND Flash Memory. It can be configured as a bootable fixed disk drive for true DISKLESS operation. PROMDISK VI includes an on-board BIOS extension ROM that contains the Datalight FlashFx integrated Flash file system and boot utilities. It is fully DOS and Windows compatible, allowing the user to copy and erase files using standard DOS commands.

PROMDISK VI can replace mechanical disk drives in systems designed to operate in harsh environments, or where weight and size are at a premium. The use of PROMDISK VI in embedded or dedicated applications offers substantial benefits in overall system cost, performance, and reliability. PROMDISK VI contains no moving parts, and incorporates low power CMOS technology to provide the highest reliability with the use of commercial grade components.

Features

* Emulates fixed disk up to 128M-bytes
* On-board BIOS ROM with Datalight FlashFx Flash File System
* SMT NAND Flash Memory for High Reliability
* Boots as drive C
* Includes ROM-DOS version 6.22
* Occupies only 16K of memory address space
* Half-size ISA type board
* QNX Version 4.23 Drivers Available
* Y2K Compliant
 
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A CF card to IDE adaptor does the same as that card. I got one and use it in my Tandy 1000TL/2. Works really good too.
 
Not to put a wet blanket on things, but the "refurb" tag on anything with flash, particularly something this old makes me a bit gun-shy. If no sort of write-leveling is present in the driver for this thing, how many writes are left (if any) on the directory/FAT blocks?

Does "refurb" mean that they replaced all of the flash?

Yeah :( I know I'm a spoilsport.
 
Not to put a wet blanket on things, but the "refurb" tag on anything with flash, particularly something this old makes me a bit gun-shy. If no sort of write-leveling is present in the driver for this thing, how many writes are left (if any) on the directory/FAT blocks?

Does "refurb" mean that they replaced all of the flash?

Yeah :( I know I'm a spoilsport.

They probably replaced nothing, they just get used computer stuff and re-sell it. Anything used comes comes with a risk of how much use did it have.

I bought two MFM hard drives on Ebay, one looked new the other looked old, both died a few months after I bought them.
 
Disk emulator no work

Disk emulator no work

vdisk.jpg



Well I finally received the card, unfortunetly it won't work in an
IBM PC or IBM PC XT, even though the manual sais it does.

The card works in a Pentium computer that has an isa slot.

Manual:

The PROMDISK Disk Emulator is a unique memory board designed to emulate DOS compatible disk
drives for use in IBM PC/XT/AT compatible computers as a replacement for a hard disk drive. It
occupies only 32K bytes of address space within the ROM Adapter address space, and is selectable
from address segment C800H through E800H on 800H boundaries. PROMDISK V supports up to
32M-bytes of Intel Flash memory and includes an on-board BIOS extension ROM containing the
Datalight CardTrick® FTL integrated Flash File System and boot utilities.


If anyone has any ideas why, speak now or forever hold your isolinear chips...

:confused: :confused: :confused: :confused: :confused: :confused:
 
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Don't have a NEC V20, but I guess I could get one and try it out..

Completely aside from the 8080 emulation mode, the V20 supports most of the 80186/8026 non-protected-mode instruction set additions.

One of the most common 8088/80286 traps wasn't the string I/O instructions but something more mundane--the shift and rotate instructions. For example, to shift AX left 4 bits on the 8088 you would to write the following

Code:
    shl    ax,1
    shl    ax,1
    shl    ax,1 
    shl    ax,1

or:

    mov   cl,4
    shl   ax,cl

Whereas, on the 80186/286/V20 you can code:

Code:
    shl    ax,4

It's such a simple thing that many programmers don't even give it a thought when coding, particularly if they've never had to code for an 8088.

A nice side benefit of a V20 is that it'll make your code run a bit faster (about 20% on the average).

Another bugaboo was use of the PUSHA/POPA, ENTER/LEAVE instructions on the 286 that aren't present on the 8088.

If you'd like, you can take a snapshot of the option ROM to this thing and post it here and I (and probably others) would be happy to poke at it with a disassembler.
 
V20

V20

How much of a speed increase would you see in a 4.77mhz vintage pc or xt with this nec chip?
 
You'd see about a 20-50% improvement, roughly.

20 to 50% is wildly optimistic. Not even NEC claimed anything in that range.

It depends on the instruction mix and what you are doing. For real life work measured with a stop watch, 5 to 15% was the norm.



Mike
 
If you boot from a floppy, can you see the PROM drive? The one I tried (in a Compaq portable) wouldn't boot, but did show up when the system was booted from a floppy. In the end I patched the Compaq's BIOS ROM to sort this out.


The cards works perfectly booting from a Pentium 233mhz computer I have that has a ISA slot.

What gets me, the company specifically states this card will run on an IBM PC/XT/AT, perhaps they left some fine print out when it comes to the PC/XT end of the rainbow?

Since the card runs perfectly on the 233, I can scan the prom to see why it isnt PC/XT friendly?
 
Like Chuck said, dump the ROM and send him/us a the dump. We can disassemble it to see what bad instructions it is using that the 8088 in your XT doesn't like.

If you need instructions on how to dump a ROM, search back in the forum for 'ROM' and 'dump' and you should find what you need.
 
The NEC V20 is also known as the uPD70108. The last time I looked, Jameco still had them for about $10 each. The 8086 replacement is the uPD70116.
 
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