Silvester wrote:Peter wrote:Derek_Stewart wrote:I hoped to use a 68060RC50A so that it would run at full speed of 50 Mhz. I did not complete this, as the Q68 got in the way.
Don't forget there never was PLD support for 50 MHz. If you use a 50 MHz oscillator with a PLD designed for higher speed, you will get inefficient DRAM timings and a wrong frame interrupt frequency. Only 60/66/80 MHz are supported.
But the 68060RC50
A runs fine at 60 MHz on that mainboard.
Slight confusion, Peter are you referring to Q40/Q60 PLD ? I think Derek was contemplating adding 68060RC50A to QXL via adapter.
Sadly from what I have seen so far, non-EC 68060 command x8 to x10 the price of EC. Didn't think SMSQ/E used MMU, must delve into Q40 source
Just to confirm, 68060 for Q40 must be have speed capability of 60, 66 or 80MHz ?
HI,
Sorry for the confusion, I was referring to the upgrading of the QXL 68EC040 to a 68060 CPU using an adapter developed for the Amiga. Which is a two board adapter that splits the 68040 5v levels and 68060 3.3v levels on separate PCBs. I have 2 sets of PCBs to be built.
The QXL 2 was fitted with a 50Mhz Oscillator which the 68040 CPU divides the clock speed by 2 to 25Mhz. So I thought why not take the Amiga 68040-060 Adapter board and fit a 68060 50Mhz to the QXL, this may run the QXL at 50Mhz, but I guess like is not that easy, and probably SMSQ/E will not work, the QL Network will not work. I will have to finish work and see if it is successful.
I have 4 QXL2 board built and a bare PCB, which I do not think they are available for sale as yet.
I never produced a Q40, these were made by Tony Firshman and later by Qbranch, the Qbranch Q40 boards had problems - poor construction and inferior components, which a friend and I stepped in to build the Q60.
We did a Q40i, with 128Mb ram, but only one was sold.
The Q60, was designed by Peter Graf and sold in a production run by D&D Systems. and 3 varieties:
Q60-60: 68060 at 60Mhz, RC CPU, with FPU, MMU
Q60-66: 68060 at 66Mhz, RC CPU, with FPU, MMU
Q60-80: 68060 at 80Mhz, LC CPU, with no FPU
For later Q60 production, there only going to the Q60-66 to made available. But this was never implemented.
Due to changes in my day time job, I had to move from Derbyshire to Cheshire, in the UK, which sort of put the Q60 on hold, and Peter gave me the Q68 to produce, which made the Q60 pushed further down the project waiting list.
After I statisfied the Q68 demand, I will look at the a possible production of a updated Q60, assumnig that the 68060 CPUs are available.
There are alot of forged 68060 CPUs so care is needed in purchasing a geniue CPU.