The Sinclair QL Forum

Happy Birthday Tetroid

I mount them with this method: Turn the QL case top 90 degree to the right. Then insert both cables straight, like into the SInclair motherboard. Then turn back the case top carefully and close it, giving the cables a 90 degree curve. Wouldn't this create a lot of stress in the membrane's ribbon ca...

Hi, The TL866II+ or TL866xx does not support the 8049 or the 8749 PLDs, I have a HiLo Systems ALL03a DOS based programmer, that can programme the 8749 and can read the 8049. I have been trying to see if new chips can be added to the TL866 series of programmer, but I can not find any information on ...

This old post covers it I think :

viewtopic.php?f=2&t=2072&p=18650&hilit= ... ery#p18650

I think the problem is the clock register could get written randomly at reset / power cycle - and the simplicity of the circuit can't prevent that. Some additional 'helper' logic is required - such as is found on the QIMI interface, to prevent any writes occurring until the voltage is stable. The 8 ...

Hi, If I follow the convert_bas to un-jumble the QEP3 ROM, the eprom data and address lines connection to the QL bus must be determined to produce the un-jumble sequence. That could be done, as the QL expansion bus is well known, and the eproms have standard jedec pinouts - so data and address line...

Hi, I had a look at the QEP III manual, which is a little lacking in a lot of places, but the Options Sub Menu indicate a Jumble option to jumble the data or address line. The manual should of really describe the jumble function. The jumble function allows any data line to be swapped for any other ...

The I2C "hardware" is a GAL chip that's used in conjucton with some I2C primitive code to give basic I2C funtionality - a driver on a seperate disk provides the rest of the code required to use I2C from Basic / Assembler. There is a new vector for I2C provided by Minerva. The Minvera I2C ...

The I2C "hardware" is a GAL chip that's used in conjucton with some I2C primitive code to give basic I2C funtionality - a driver on a seperate disk provides the rest of the code required to use I2C from Basic / Assembler. There is a new vector for I2C provided by Minerva.

I posted pictures earlier in this thread of the IC that needs to be replaced in the video circuit - along with the link to the icl information that explains which chip is swapped for which other chip (74LS240 to 74LS244) from memory.