The Sinclair QL Forum

'Two interfaces and a non-switch Epson keyboard. Oh well... More on the interfaces later. Mark, have you tried yours yet? Do you mean the keyboard or the interface? Or both? Anyway, at the moment, the answer to all the above questions is "no, not yet". On Thursday I spent about an hour re...

Epson Keyboard Pictures Mark

Epson Keyboard

Having received my parcel of goodies, I removed the case of the Epson keyboard to see inside. It is a membrane type mounted on a curved metal plate. Just thought I would mention it, as this was being discussed earlier in the thread.

One SRAM 512k x 8 for £2.79+VAT, not going to break the bank

Mark

NEC FD1037A Floppy Disk Drives Here are some pictures found as a result of a internet search. The first one clearly shows that it uses +5V and +12V The rest all look like single +5V supply types. http://www.harddrives-usa.com/files/thumbnail/fd1037a2.jpg http://www.topkapibilgisayar.com/image/cache...

Yes, if the drives only need +5V, the 7805 will supply them. This was my first thought, that the drives are single supply models. However, when I searched for information on them, I found a picture showing the model number and also showing the power requirements, which stated +5V and +12V. So it loo...

Mark, what do you mean? Why SRAM? Or, what do you mean, "modern" DRAM? As in... DDR perhaps? I mean use one (or maybe two) 512k x 8 bit SRAM chips instead of the DRAM chips used on a Gold card (for example) so that the QL has more than it's standard 128k RAM. I'm not sure where the price ...

Yikes! Transformer, rectifier bridge, shitty capacitors, 7812, no filtering? Looks more like the rectified 9V ac from the transformer is smoothed by the large blue electrolytic capacitor, this the feeds the +12V dc supply to the FDD (but off load will be about 13V). Meanwhile this supply also feeds...

Looks fixable to me :mrgreen: (normal get out clause may apply :P ) With the unit unplugged you are looking to see low resistance readings (from zero ohms to about 10 ohms max) across the fuse, the primary windings and the secondary windings. Check to see if the board has been coated in a protective...

And (*drum roll please*), tenthly, would we want SRAM chips instead of (I presume) fast page DRAM (can't be bothered to go and check at the moment) OR we would need some err, modern DRAM modules (with their own "new to us" access timing)...

Mark