CPLD replacement for ZX8301

[bwinkel67]

...but If you mean the bar width this is a change I did in the test program.

I was referring to the bar width (black boarders)...so the program just drew them smaller, leaving black gaps.

[Andrew]

Would it be possible to have an extension, to use 16 colors in QDOS? Or a SMSQE 16 colors driver?

[lliont]

Would it be possible to have an extension, to use 16 colors in QDOS? Or a SMSQE 16 colors driver?

It is possible to add commands to print, plot,... in 16 colors to SuperBasic.
Maybe there is a better way to have 16 colors by replacing system routines in QDOS ?

[Andrew]

Would it be possible to have an extension, to use 16 colors in QDOS? Or a SMSQE 16 colors driver?

It is possible to add commands to print, plot,... in 16 colors to SuperBasic.
Maybe there is a better way to have 16 colors by replacing system routines in QDOS ?

There are a lot of commands that use color as a parameter - and we also need a way to maintain compatibility with 4/8 color mode

By the way: will the new ZX8301 have 8 colors in mode 4 ?

[bwinkel67]

Are you getting new colors or are you just able to display the low resolution colors in high resolution?

[lliont]

Currently there is the option of 8 new colors in low resolution after adding 3 resistors on the motherboard for the composite video output, no new colors in mode 4.
To see the new colors if not using composite video you need a RGBI monitor and make a compatible connector or make a new connector and mix the RGB signals with the extra bit using a simple circuit, I may do it on the pcb in a future pcb version so a new connector to not be needed for the RGB.

I finally managed to fit the ULA to an EPM7128S cpld. I rewrote a section of the code and it now fits.

[tofro]

Software-wise: Instead of extending MODE 8 to 16 colours (which would need adaption of ROM code in a huge amount of places) it would probably be way easier to implement a BRIGHT <0|1> keyword that flips the 4th colour bit like it was done on the ZX Spectrum. As we have source code for Minerva, that should probably be the first task to attack.

[Martin_Head]

Would it be possible to make the mode 4 colours reprogrammable. So that say PAPER 0 would give blue.

[lliont]

Would it be possible to make the mode 4 colours reprogrammable. So that say PAPER 0 would give blue.

Yes this can be implemented in hardware for example by reading dip switches that set the color.
But it can be set by software by decoding an address to write at a register in the cpld.

[lliont]

While I am waiting to receive the ic to build the last (?) version of the pcb with the smd EPM7128S cpld, I added a register in the cpld to implement in software the switching between 16 colors and flash.
The switch to 16 colors in mode 8 now is controlled by setting the bit 0 of the byte at address 98400 decimal. I hope this address is not used by other hardware in some way.

But I also added the choice of 3 more color combinations in mode 4 controlled by bit1 and bit2 of the same byte. Setting b2b1 to 00 is the default color.

01 gives:

10 gives:

11 gives:

karate in green and blue