cdtv rom's

[voyager]

I bought myself a nice cdtv in mind condition, most you see were left to rot in basements but this one looks almost new ;-)

I found the cdtv roms on cdtv.org.uk and I burnt them onto 128KB eproms with no success. I used 32 pin National 27c010 150 Ms and the 32 pin ST M27c1001 100Ms. The unit boots direct tot the kickstart rom. So what is the correct eprom that the cdtv can use?

I found that the new roms are a lot bigger than the old ones. The old ones are 32KB? That’s the most I can program into a eprom with 28 pins. Using the 32 pin socket I can program 128 KB seems logical to me as the files I found are 128 KB (byte not bit)

The version number jumps up quite a lot to version 2.3 what are the main differences? Can 2.3 use 2.04 or 3.0 kickstart roms? What about 2.9 are there any bin files for those?

I also want to say thanks to al the people that replied on my hd topic, to bad the waw scsi interface is so hard to find. Has anyone one for sale? Maybe a dead one.

Kind Regards Sebastian,-

[Doobrey]

Looking at the CDTV schematics, it uses 27C1000 EPROMS. (IIRC, pin compatible to 27C301)

The only difference between 27C1001 and 27C1000 seems to be 2 pins are swapped, so you could easily hack up a personality module from a pair of 32 pin DIL sockets. :hammer:
On the 27C1001, pin 2=A16, pin 22= /OE
On the 27C1000, pin 2= /OE, pin 22= A16.

As for the 2.9 ROM,did you mean 2.7 ?
The 2.3 ROM is actually 2.30, and is newer than 2.7 ( by about a 3 months or so)

[karsten]

So what is the correct eprom that the cdtv can use?

As said before 27c1001 work fine if you swap the two pins (but 2<>24 not 22)

I found that the new roms are a lot bigger than the old ones. The old ones are 32KB?

Where did you find that? AFAIK all CDTV extended ROMs are 2x128KB

The version number jumps up quite a lot to version 2.3 what are the main differences?

First one thing. It's version 2.30 and not 2.3 (not the same as it's not a number, but a version number; 2=major version, 30=minor version). Also the version numbers in ascending order are as follows as can be found out by checking the dates (listed are the versions where I know an image can be found somewhere):
ß2.9 (it is not the latest as written at cdtv.org.uk, it's a beta version)
0.1 (gamma version)
1.0 (the one from the original CDTVs)
2.7 (don't know where that comes from, does anyone know?)
2.30 (from A570)

cdtv.org.uk also states there's a 3.2 for the CDTV-CR, but I haven't seen it yet and don't know if that would work in a CDTV

Can 2.3 use 2.04 or 3.0 kickstart roms?

2.30 works with higher Kickstarts as 2.7 does too

What about 2.9 are there any bin files for those?

In the 2.9 archive at cdtv.org.uk (file ROMCode). You would need to unpack the dms and extract the file and split it in even/odd, but as I said, this version is actually the oldest (it's ß2.9)

to bad the waw scsi interface is so hard to find. Has anyone one for sale?

Actually, you can buy a licenced version of the W.A.W. SCSI controller at http://www.cnctechniker.de/ (click on Amiga, ordering from mid-September again as he's busy currently). Don't know if he speaks English, also the manual is in German too (it's the W.A.W. manual), but it's not really needed. Price is 70 Euro+shipping

[Doobrey]

karsten wrote:
2.30 (from A570)

Phew , thanks for the reminder,I thought I was going mad earlier  :lol:

Just looked a 1.0,2.7 and 2.30 and saw they all had the "A590/A2091 IORequest handler" resident.
But then saw the "A690ID" resident in the 2.30 ROM.
I could have sworn it was in the 2.7 ROM.
Sometimes I wish my brain had a parity check for error detection!

[alexh]

I needed two 27C1000's the other month and had to buy 100 units (it was a VERY good price).

Despite being difficult to find, I found them in 10 mins.

Should you be that way inclined you can also use 27C1000's in Atari STe as TOS ROMS

[voyager]

I’am going to try the 2 swap pin solution with the  27c1001.

Why I thought that the cdtv roms are only 32KB is because it seems I can only program  32KB in a 28 pin eprom. The cdtv uses 28 pin roms so I thought it must be 32 KB roms.

The Eprom burner a all writer could not recognise the existing roms in the unit.

YES that’s the page I was looking for and could not find for months !! I knew there was someone building interfaces. I will drop him a line.

Well the next opportunity for me to burn a rom is next Wednesday so for now thanks to all.

   

[karsten]

The cdtv uses 28 pin roms so I thought it must be 32 KB roms.

No, it uses 32 pin roms.

[voyager]

2 sockets of 32 pins 2 chips with 28 pin 4 pin unused per socket.

[karsten]

Not sure which ones are unused, looking at the schematics, I couldn't find 4 unused (and each rom is 128KB and it clearly has 17 adress lines)

[voyager]

If you take the cdtv unit with the front before you and you take of the top cover the bottom 4 pin's are not in use. This is not normal?

I   I
I   I
I   I
I   I
I   I
I   I
I   I
I   I
I   I
I   I
I   I
I   I
I   I
I   I
X   X
X   X

[karsten]

That would be pin 1 (Vpp), pin 2 (OE), pin 31 (PGM), pin 32 (Vcc). I doubt they would work if all 4 pins are unused and still there would be 17 address lines connected to the address bus

[voyager]

[karsten]

Never seen ROMs with those pins missing, do they work that way, i.e. do you get the CDTV boot screen or a Kickstart boot screen? I would think you would need at least Vcc for the ROMs to operate. Still doesn't explain how do you get to the 32 KB, as there are no address lines missing.

[karsten]

Looking at BBOAH, there indeed seem to be 28 pin ROMs. But those are no EPROMs as there is no quartz window for erasing. It could be that this is an OTP ROM, which I doubt as it would have not enough pins for programming, I think it's a ROM chip and Vcc connects also to pin 28 of the ROM (would be pin 30 of the EPROM, no internal connection on a 27c1000). In my CDTV there was originally a 27C1000 EPROM with 32 pins, so they used both.

[voyager]

Yes it works normal ;-) and yes it looks like it's a OTP, but the question remains can i stil use eproms if I switch the 2 pin's ?

32KB, A friend of my lookt in his eprom database and the bigest one he could find with 28 pin's was a 32KB prom Any bigger it would have 32 pins. But it seems we where wrong ;-)

REF 2.2.1 mainboard

391009-01 u34 / u35
(c) 1991 CBMV1.0
321BPCL6 000
1G1 Japan