CPCWiki forum

General Category => Amstrad CPC hardware => Topic started by: Spirantho on 18:45, 12 January 14

Title: Just stocked up on Z80A and MC6845P chips...
Post by: Spirantho on 18:45, 12 January 14
Hi everybody,
I just bought some chips from China, and to make the postage worthwhile I had to buy some other chips.
So, I now have 50 NOS D780C-1 (Z80A) CPUs, and 49 MC6845P CRTCs (only 49 because I've already used one to repair a CPC464 :) ). They're all very late datecodes (The D780C-1 are 1991, the 6845s around the same I think) and obviously I'll test them before sending them, but I have confidence they'll work. I tried one of each chip already and they're perfect.
Therefore, if anyone wants one or several just let me know as I can always get more. :) I'm looking for £5 for each including postage inside the UK, excluding postage outside the UK, or less if you buy several at once.
I didn't want to put this in the classified because I thought it may be of interest to people repairing CPCs - feel free to move it if you like.
Title: Re: Just stocked up on Z80A and MC6845P chips...
Post by: arnoldemu on 20:42, 12 January 14
Quote from: Spirantho on 18:45, 12 January 14
Hi everybody,
I just bought some chips from China, and to make the postage worthwhile I had to buy some other chips.
So, I now have 50 NOS D780C-1 (Z80A) CPUs, and 49 MC6845P CRTCs (only 49 because I've already used one to repair a CPC464 :) ). They're all very late datecodes (The D780C-1 are 1991, the 6845s around the same I think) and obviously I'll test them before sending them, but I have confidence they'll work. I tried one of each chip already and they're perfect.
Therefore, if anyone wants one or several just let me know as I can always get more. :) I'm looking for £5 for each including postage inside the UK, excluding postage outside the UK, or less if you buy several at once.
I didn't want to put this in the classified because I thought it may be of interest to people repairing CPCs - feel free to move it if you like.
The MC6845P are type 2s btw.
Title: Re: Just stocked up on Z80A and MC6845P chips...
Post by: Spirantho on 21:06, 12 January 14
Am I right in thinking it'll fit any of the original (non-"plus") Amstrads?
How many programs rely on the CRTC being a particular type?
Title: Re: Just stocked up on Z80A and MC6845P chips...
Post by: Bryce on 21:11, 12 January 14
All CRTCs in classic CPCs are pin compatible. You can use those parts in any Classic CPC. The Gate-array was the only chip that changed pinout between versions.

Bryce.
Title: Re: Just stocked up on Z80A and MC6845P chips...
Post by: Spirantho on 21:16, 12 January 14
Thought so. That's good. :)
Title: Re: Just stocked up on Z80A and MC6845P chips...
Post by: fgbrain on 22:26, 12 January 14
Most hardware demos dont work with  CRTC type 2.. Although some can be fixed..
The only game I had problem with, was Zaptballs. When I changed to type 0, no problem!!
Title: Re: Just stocked up on Z80A and MC6845P chips...
Post by: Bryce on 22:37, 12 January 14
If my CPC is broken, I'd rather have a type 2 CRTC than no CRTC. Any spare parts for the CPC are good spare parts.

Bryce.
Title: Re: Just stocked up on Z80A and MC6845P chips...
Post by: MacDeath on 00:44, 13 January 14
what about a 6mhz or 8mhz CPC then ?


I know that to overclock the CPC would modify the display (reduced horizontally...
Could it be changed so the computer runs faster with no alteration from the display ?


I guess more components would need to be changed, not just the Z80...
Title: Re: Just stocked up on Z80A and MC6845P chips...
Post by: Bryce on 09:26, 13 January 14
Quote from: MacDeath on 00:44, 13 January 14
what about a 6mhz or 8mhz CPC then ?


I know that to overclock the CPC would modify the display (reduced horizontally...
Could it be changed so the computer runs faster with no alteration from the display ?


I guess more components would need to be changed, not just the Z80...

This has been discussed numerous times in many different threads here. The quick answer is "No.", for the long answer check the other threads.

Bryce.
Title: Re: Just stocked up on Z80A and MC6845P chips...
Post by: arnoldemu on 09:54, 13 January 14
Quote from: Spirantho on 21:16, 12 January 14
Thought so. That's good. :)
replacing a broken crtc with a working crtc is always good.
Title: Re: Just stocked up on Z80A and MC6845P chips...
Post by: TFM on 23:15, 13 January 14
Quote from: MacDeath on 00:44, 13 January 14
what about a 6mhz or 8mhz CPC then ?


I know that to overclock the CPC would modify the display (reduced horizontally...
Could it be changed so the computer runs faster with no alteration from the display ?


I guess more components would need to be changed, not just the Z80...


Yes, with huge effort. BUT why doing that? The 6 MHz CPC offers you a video mode with mode 1 resolution and Mode 0 colors! Can't beat that.  :)
Title: Re: Just stocked up on Z80A and MC6845P chips...
Post by: MacDeath on 22:15, 14 January 14
and border when in full screen ?  ;D
Title: Re: Just stocked up on Z80A and MC6845P chips...
Post by: TFM on 22:42, 14 January 14
Actually nearly no border. And that's good. The use of a border is minor imho.[nb]The only cool usage of a border I've ever seen was a demo/routine which could display a sprite in the border. Cool but ... what?[/nb]
Title: Re: Just stocked up on Z80A and MC6845P chips...
Post by: Bryce on 10:02, 15 January 14
The border is important for the flashing pattern when I load tapes! :)

Bryce.
Title: Re: Just stocked up on Z80A and MC6845P chips...
Post by: TFM on 18:04, 15 January 14
Only an idiot would expand a 6128 to a 6 MHz workstation and then still use taps as medium.  ;)
Title: Re: Just stocked up on Z80A and MC6845P chips...
Post by: Gryzor on 19:58, 15 January 14
Quote from: Bryce on 10:02, 15 January 14
The border is important for the flashing pattern when I load tapes! :)

Bryce.


Same here. I do CRC checks just by looking at it.
Title: Re: Just stocked up on Z80A and MC6845P chips...
Post by: Bryce on 22:27, 15 January 14
Quote from: Gryzor on 19:58, 15 January 14

Same here. I do CRC checks just by looking at it.

I don't do anything clever with it, I just like flashing colours :)

Bryce.
Title: Re: Just stocked up on Z80A and MC6845P chips...
Post by: Gryzor on 22:33, 15 January 14
Clearly, you've never calculated CRCs while on hallucinogenics. Utter fun!
Title: Re: Just stocked up on Z80A and MC6845P chips...
Post by: ralferoo on 09:23, 17 January 14
Quote from: Gryzor on 22:33, 15 January 14
Clearly, you've never calculated CRCs while on hallucinogenics. Utter fun!
Isn't that a prerequisite for doing CRCs manually?
Title: Re: Just stocked up on Z80A and MC6845P chips...
Post by: Gryzor on 16:56, 17 January 14
Depends on whether you want them to work afterwards!
Powered by SMFPacks Menu Editor Mod