The same QL with a Trump Card is faster.
I wrote a little program:
Code: Select all
10 CLS
20 SDATE 2020,7,22,0,0,0
30 PRINT DATE$
40 FOR x=0 TO 10000
50 AT 1,0
60 PRINT x
70 NEXT x
80 PRINT DATE$
Code: Select all
10 CLS
20 SDATE 2020,7,22,0,0,0
30 PRINT DATE$
40 FOR x=0 TO 10000
50 AT 1,0
60 PRINT x
70 NEXT x
80 PRINT DATE$
That is caused by the memory layout of the QL that shares screen memory and main memory. The lower 128k RAM are being accessed both by the CPU and the ULA, making memory accesses to that region effectively ~50% slower (because CPU and ULA have to wait for each other until an access to that memory is finished).stephen_usher wrote:I made a bit of a personal discovery last night whilst just writing a test program when mucking about with the B&W telly.
The same QL with a Trump Card is faster.
On the unexpanded QL (JS ROM) this takes either 3m 15s or 3m 17s (nothing in between and it seems random which one you get) but with the Trump Card installed it's 3m 2s or 3m 3s. That's quite a difference. Any idea why this may be the case? These are both with a clean power-up and the program typed in.
Nope, and this is why really well-designed memory extensions can speed up a QL significantly.stephen_usher wrote:Ah, I didn't realise that above 128K it was uncontended, I thought that it was all compromised by video access.