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#1
Technical support - Hardware related / Re: CPC 6128 - white screen, b...
Last post by McArti0 - Today at 13:26Ok. Make OR Gate on breadbord. (From 2 NOR gate in 74Ls02). 
#2
M
Technical support - Hardware related / Re: CPC 6128 - white screen, b...
Last post by mmldrm - Today at 12:23Finally the 74LS02 has arrived!
I will try the above tests too, if I understand them.
My oscilloscope is a Zoyi ZT-702S: https://zoyitools.com/product/zt-702s/
I found it for £43, and figured it's something I can use for years after this. This is true for the breadboard and components I bought for the tests - I like playing with electronics and would like to do more hardware projects in the future.
If these tests from @McArti0 can reduce the number of chips that I desolder and replace, I am less likely to destroy the motherboard in the process. Unorthodox, but I'm happy to proceed with caution on this.
Thanks for staying with me this far on the journey. I know there is a variety of opinions on the path we have taken.
I will try the above tests too, if I understand them.
My oscilloscope is a Zoyi ZT-702S: https://zoyitools.com/product/zt-702s/
I found it for £43, and figured it's something I can use for years after this. This is true for the breadboard and components I bought for the tests - I like playing with electronics and would like to do more hardware projects in the future.
If these tests from @McArti0 can reduce the number of chips that I desolder and replace, I am less likely to destroy the motherboard in the process. Unorthodox, but I'm happy to proceed with caution on this.
Thanks for staying with me this far on the journey. I know there is a variety of opinions on the path we have taken.
#3
I always really liked the original CPC loading screen, even if Trantor looks like David Lee Roth! 
Your new version looks great.
Your new version looks great.
#4
You really ought to hurry up and announce them so we can start being impatient.
#5
Quote from: Benedikt on Yesterday at 20:22And is there any way to just read a specific sector in a file system agnostic way using Basic and to run it as machine code?The only way from BASIC is |CPM which loads track 0, side 0 sector &41. It will only load 512 bytes though (whatever is booted is then expected to load the rest).
Putting a write-protected system file in a known sequence of sectors is solved problem.
The question is about bootstrapping, i.e a DOS with the relevant capabilities is not already running.
#6
There is
BPB_RsvdSecCnt
"Number of reserved sectors in the Reserved region of the volume
starting at the first sector of the volume. This field must not be 0.
For FAT12 and FAT16 volumes, this value should never be
anything other than 1. For FAT32 volumes, this value is typically
32."
So as all discs are FAT12, there is no chance for having additional reserved sectors at fixed LBAs beside the boot sector.
But you can always reserve clusters on a FAT device using the FAT itself without assigning them to a file (a PC then may want to repair the disc ). If you have always the same disc size, this could be done at fixed LBAs (tracks/sectors).
BPB_RsvdSecCnt
"Number of reserved sectors in the Reserved region of the volume
starting at the first sector of the volume. This field must not be 0.
For FAT12 and FAT16 volumes, this value should never be
anything other than 1. For FAT32 volumes, this value is typically
32."
So as all discs are FAT12, there is no chance for having additional reserved sectors at fixed LBAs beside the boot sector.
But you can always reserve clusters on a FAT device using the FAT itself without assigning them to a file (a PC then may want to repair the disc
). If you have always the same disc size, this could be done at fixed LBAs (tracks/sectors). #7
@Benedikt
I didn't want to make an interface between the socket and the z80 at all costs. Fun for 80 pins.
Besides, in my micro fpga I have no free input left and only one gate.
I used SLG46826 because it has NVM configuration. I could probably fit everything in 46533 but there is OTP (PROM)
It is enough to confirm that OUT (C),0 is the only significant compatibility problem.
I didn't want to make an interface between the socket and the z80 at all costs. Fun for 80 pins.
Besides, in my micro fpga I have no free input left and only one gate.
I used SLG46826 because it has NVM configuration. I could probably fit everything in 46533 but there is OTP (PROM)
It is enough to confirm that OUT (C),0 is the only significant compatibility problem.
#8
B
Amstrad CPC hardware / Re: Zilog Z84C0020PEG in my CP...
Last post by Benedikt - Yesterday at 21:55Quote from: McArti0 on Yesterday at 21:29Hardware patch converts OUT(c),0 [ED 71] to IN(c) [ED 70] next pushing 00 on the data bus and forcing RD Hi and WR Lo. short circuit current ~2x20 mA CMOS outputs are very strong.Wouldn't it be possible to just put XORs in the /WR and /RD lines to selectively invert them?
Correct The WR and RD signals should be gated.
#9
External hardware Z84C for OUT (c),0 working and ALL SOFT WORKING 
Semi HARDCORE version.
Hardware patch converts OUT(c),0 [ED 71] to IN(c) [ED 70] next pushing 00 on the data bus and forcing RD Hi and WR Lo. short circuit current ~2x20 mA CMOS outputs are very strong.
Correct The WR and RD signals should be gated.
Now I'm waiting to see what goes first: the RD and WR outputs in the Z80 or the forcing outputs in the SLG
The patch was sewn into the SLG46826v-DIP
Maybe someone would like to create such an interface in the version between Z84cmos and the socket?
Hardware Patch Z84C SemiHardcore emulated
Greetings to All McArti0.
Semi HARDCORE version.
Hardware patch converts OUT(c),0 [ED 71] to IN(c) [ED 70] next pushing 00 on the data bus and forcing RD Hi and WR Lo. short circuit current ~2x20 mA CMOS outputs are very strong.
Correct The WR and RD signals should be gated.
Now I'm waiting to see what goes first: the RD and WR outputs in the Z80 or the forcing outputs in the SLG
The patch was sewn into the SLG46826v-DIP
Maybe someone would like to create such an interface in the version between Z84cmos and the socket?
Hardware Patch Z84C SemiHardcore emulated
Greetings to All McArti0.
#10
I adapted the loading screen of Trantor from the C64 version by Paul Docherty, which is way better than the one made by Andy Jones for the CPC.