DKB 1240, Melody Z2, Spectrum 28/24

DKB 1240 - $90 USD: Came with an A1200 I purchased from a fellow here a while back. This appears to be the "Mongoose", which originally came clocked at 50MHz. *SOLD to bebek*

When I received the card, it had a 40MHz CPU installed, and a rather crudely soldered 40MHz oscillator in place. From what I gathered researching usenet a bit, the Mongoose was often notoriously unstable at the default 50MHz. The fix from DKB was to either RMA the card for a refund, hope for a fixed production run, or downclock to 40MHz. No idea if the fault was with the 1240 itself, or due to varying revisions of the 1200 motherboard.

With a 50MHz CPU and oscillator, the card crashed on my test A1200 in a matter of 1-10 minutes. 40MHz was generally stable, but still crashed on occasion if left on long enough. Next I tried 32MHz, which I found to be 100% reliable - therefore, I cannot guarantee the card to be working at anything other than 32MHz. I cleaned up the cruddy soldering and installed a machine-pin oscillator, so you can do your own testing. You'll need to cut out a small section of the plastic ridge on the 1200 trapdoor, if you want it closed with the oscillator installed. It might barely clear with a lower profile oscillator.

CPU is an "MC" rated 40MHz part, the FPU is "XC" rated at 50MHz. 16MB RAM installed, accepts up to a whopping 128MB.

Melody Z2 - $250 USD: Clean and in perfect working condition. I've only seen 2 for sale in the entire time I've been collecting Amiga gear. Superb sound quality, does MP2 in hardware - but not MP3.

Spectrum 28/24 - $175 USD: Like the Melody, clean and works perfectly. Card is both Zorro 2 and Zorro 3, and picks up a little bit of performance on the latter. The picture quality of the Spectrum is very nice, much better than my old CV64/3D. *SOLD to bdb*

All prices include worldwide shipping, buyer pays PayPal fees.

interested in dkb

Also interested in DKB!

... withdraw...

interested too.

1240 sold to bebek, will update with shipping confirmation tomorrow morning.

Interested in Spectrum. PM to follow.

---------- Post added at 19:31 ---------- Previous post was at 18:40 ----------

EGS Spectrum 24/28 card payment made.

Spectrum now sold, will update the thread tomorrow after shipping along with the 1240. :thumbsup:

Just wanted to say that my Mongoose does not show any instability at 50MHz.

My understanding from browsing the usenet archive was that only certain batches were affected:

Quote:

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The last two production runs of the Mongoose have resulted in unstable accelerators that cause A1200's to crash frequently. DKB told me a few weeks ago that they'd determined that faulty chips from one of their suppliers were to blame. They were still trying to get the problem resolved so that they could start making and testing Mongooses again.

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There's more there if you want to dig. I have no idea if that's what the deal is with this particular card, but it was my suspicion as down-clocking remedied the crashing (which was also mentioned elsewhere on usenet). The behavior definitely seemed heat related, and I thought about trying to isolate the offending chip before I ran out of time (had to get the gear off the kitchen table) and put my gaming 1200 back together with another '030 accelerator.

If I found a Mongoose fully working at 50Mhz I would buy it in a second. It's a really sweet card.

Packages sent, and relevant deetz sent to both buyers via pmail. :pint: