25 Jan
2017
25 Jan
'17
6:47 p.m.
Evening folks,
Could a stuck bit or floating pin cause this address sequence?
0.142261562500000,'3896' (0x0F38) 0000111100111001
0.142262937500000,'3897' (0x0F39) 0000111100111010
0.142264250000000,'3898' (0x0F3A) 0000111100111011
0.142265562500000,'3899' (0x0F3B) 0000111100111100
0.142266937500000,'3900' (0x0F3C) 0000111100111101
0.142268250000000,'3901' (0x0F3D) 0000111100111110
0.142269562500000,'3902' (0x0F3E) 0000111100111111
0.142270937500000,'61618' (0xF0B2) 1111000010110010 (should be 0x0FB2?)
0.142271937500000,'61619' (0xF0B3) 1111000010110011 (should be 0x0FB3?)
0.142261562500000,'3896' (0x0F38) 0000111100111001
0.142262937500000,'3897' (0x0F39) 0000111100111010
0.142264250000000,'3898' (0x0F3A) 0000111100111011
0.142265562500000,'3899' (0x0F3B) 0000111100111100
0.142266937500000,'3900' (0x0F3C) 0000111100111101
0.142268250000000,'3901' (0x0F3D) 0000111100111110
0.142269562500000,'3902' (0x0F3E) 0000111100111111
0.142270937500000,'61618' (0xF0B2) 1111000010110010
0.142271937500000,'61619' (0xF0B3) 1111000010110011
0.142261562500000,'3896' (0x0F38) 0000111100111001
0.142262937500000,'3897' (0x0F39) 0000111100111010
0.142264250000000,'3898' (0x0F3A) 0000111100111011
0.142265562500000,'3899' (0x0F3B) 0000111100111100
0.142266937500000,'3900' (0x0F3C) 0000111100111101
0.142268250000000,'3901' (0x0F3D) 0000111100111110
0.142269562500000,'3902' (0x0F3E) 0000111100111111
0.142270937500000,'61618' (0xF0B2) 1111000010110010
0.142271937500000,'61619' (0xF0B3) 1111000010110011
My Executel ROM disassembly puts this block of code between 0x0F38 and
0x0F3E:
0F38 L0F38:
0F38 : 7B "{" [4] mov a,e
0F39 : 95 " " [4] sub l
0F3A : 5F "_" [4] mov e,a
0F3B : 7A "z" [4] mov a,d
0F3C : 9C " " [4] sbb h
0F3D : 57 "W" [4] mov d,a
0F3E : C9 " " [10] ret
Does that make sense? I might not have a full disassembly since L0F38 is
only called from two places and neither of them jump back to 0x0FB2 but I
know that doesn't necessarily mean it's wrong.
Cheers,
--
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?
25 Jan
25 Jan
8:02 p.m.
New subject: FW: 8085 Address Decoding
Hi folks,
Apologies if this gets posted twice, I noticed I'd sent it from my
non-cctalk address.
A
--
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?
------ Forwarded Message
From: Adrian Graham <witchy at binarydinosaurs.co.uk>
Date: Wed, 25 Jan 2017 23:47:04 +0000
To: "Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org>
Conversation: 8085 Address Decoding
Subject: 8085 Address Decoding
Evening folks,
Could a stuck bit or floating pin cause this address sequence?
0.142261562500000,'3896' (0x0F38) 0000111100111001
0.142262937500000,'3897' (0x0F39) 0000111100111010
0.142264250000000,'3898' (0x0F3A) 0000111100111011
0.142265562500000,'3899' (0x0F3B) 0000111100111100
0.142266937500000,'3900' (0x0F3C) 0000111100111101
0.142268250000000,'3901' (0x0F3D) 0000111100111110
0.142269562500000,'3902' (0x0F3E) 0000111100111111
0.142270937500000,'61618' (0xF0B2) 1111000010110010 (should be 0x0FB2?)
0.142271937500000,'61619' (0xF0B3) 1111000010110011 (should be 0x0FB3?)
0.142261562500000,'3896' (0x0F38) 0000111100111001
0.142262937500000,'3897' (0x0F39) 0000111100111010
0.142264250000000,'3898' (0x0F3A) 0000111100111011
0.142265562500000,'3899' (0x0F3B) 0000111100111100
0.142266937500000,'3900' (0x0F3C) 0000111100111101
0.142268250000000,'3901' (0x0F3D) 0000111100111110
0.142269562500000,'3902' (0x0F3E) 0000111100111111
0.142270937500000,'61618' (0xF0B2) 1111000010110010
0.142271937500000,'61619' (0xF0B3) 1111000010110011
0.142261562500000,'3896' (0x0F38) 0000111100111001
0.142262937500000,'3897' (0x0F39) 0000111100111010
0.142264250000000,'3898' (0x0F3A) 0000111100111011
0.142265562500000,'3899' (0x0F3B) 0000111100111100
0.142266937500000,'3900' (0x0F3C) 0000111100111101
0.142268250000000,'3901' (0x0F3D) 0000111100111110
0.142269562500000,'3902' (0x0F3E) 0000111100111111
0.142270937500000,'61618' (0xF0B2) 1111000010110010
0.142271937500000,'61619' (0xF0B3) 1111000010110011
My Executel ROM disassembly puts this block of code between 0x0F38 and
0x0F3E:
0F38 L0F38:
0F38 : 7B "{" [4] mov a,e
0F39 : 95 " " [4] sub l
0F3A : 5F "_" [4] mov e,a
0F3B : 7A "z" [4] mov a,d
0F3C : 9C " " [4] sbb h
0F3D : 57 "W" [4] mov d,a
0F3E : C9 " " [10] ret
Does that make sense? I might not have a full disassembly since L0F38 is
only called from two places and neither of them jump back to 0x0FB2 but I
know that doesn't necessarily mean it's wrong.
Cheers,
--
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?
------ End of Forwarded Message
8:09 p.m.
On 26/01/2017 10:17, Adrian Graham wrote:
Evening folks,
Could a stuck bit or floating pin cause this address sequence?
0.142261562500000,'3896' (0x0F38) 0000111100111001
0.142262937500000,'3897' (0x0F39) 0000111100111010
0.142264250000000,'3898' (0x0F3A) 0000111100111011
0.142265562500000,'3899' (0x0F3B) 0000111100111100
0.142266937500000,'3900' (0x0F3C) 0000111100111101
0.142268250000000,'3901' (0x0F3D) 0000111100111110
0.142269562500000,'3902' (0x0F3E) 0000111100111111
0.142270937500000,'61618' (0xF0B2) 1111000010110010 (should be 0x0FB2?)
0.142271937500000,'61619' (0xF0B3) 1111000010110011 (should be 0x0FB3?)
0.142261562500000,'3896' (0x0F38) 0000111100111001
0.142262937500000,'3897' (0x0F39) 0000111100111010
0.142264250000000,'3898' (0x0F3A) 0000111100111011
0.142265562500000,'3899' (0x0F3B) 0000111100111100
0.142266937500000,'3900' (0x0F3C) 0000111100111101
0.142268250000000,'3901' (0x0F3D) 0000111100111110
0.142269562500000,'3902' (0x0F3E) 0000111100111111
0.142270937500000,'61618' (0xF0B2) 1111000010110010
0.142271937500000,'61619' (0xF0B3) 1111000010110011
0.142261562500000,'3896' (0x0F38) 0000111100111001
0.142262937500000,'3897' (0x0F39) 0000111100111010
0.142264250000000,'3898' (0x0F3A) 0000111100111011
0.142265562500000,'3899' (0x0F3B) 0000111100111100
0.142266937500000,'3900' (0x0F3C) 0000111100111101
0.142268250000000,'3901' (0x0F3D) 0000111100111110
0.142269562500000,'3902' (0x0F3E) 0000111100111111
0.142270937500000,'61618' (0xF0B2) 1111000010110010
0.142271937500000,'61619' (0xF0B3) 1111000010110011
My Executel ROM disassembly puts this block of code between 0x0F38 and
0x0F3E:
0F38 L0F38:
0F38 : 7B "{" [4] mov a,e
0F39 : 95 " " [4] sub l
0F3A : 5F "_" [4] mov e,a
0F3B : 7A "z" [4] mov a,d
0F3C : 9C " " [4] sbb h
0F3D : 57 "W" [4] mov d,a
0F3E : C9 " " [10] ret
Does that make sense? I might not have a full disassembly since L0F38 is
only called from two places and neither of them jump back to 0x0FB2 but I
know that doesn't necessarily mean it's wrong.
Cheers,
Hi Adrian,
The instruction at 0x0F3E is RET, so it's going to read two bytes off
the stack and jump to it. This is what you're seeing at 0xF0B2 and
0xF0B3. I'd suggest you look at how RAM is addressed at the top of
memory space and see if it's correct.
Alexis.
26 Jan
26 Jan
3:41 a.m.
On 26/01/2017 01:09, "Alexis Kotlowy" <thrashbarg at kaput.homeunix.org>
wrote:
I was afraid someone might say that. Whilst I don't have a memory map for
this system (or any other docs apart from the ones I'm writing myself) I did
notice last night that CAS-1 was missing. RAM is laid out like a CBM PET
with 16x 4116 DRAMs split into lower and upper blocks. RAS and CAS-0 are
pulsing.
More probing tonight then!
--
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?
My Executel
ROM disassembly puts this block of code between 0x0F38 and
0x0F3E:
0F38 L0F38:
0F38 : 7B "{" [4] mov a,e
0F39 : 95 " " [4] sub l
0F3A : 5F "_" [4] mov e,a
0F3B : 7A "z" [4] mov a,d
0F3C : 9C " " [4] sbb h
0F3D : 57 "W" [4] mov d,a
0F3E : C9 " " [10] ret
Does that make sense? I might not have a full disassembly since L0F38 is
only called from two places and neither of them jump back to 0x0FB2 but I
know that doesn't necessarily mean it's wrong.
Cheers,
Hi Adrian,
The instruction at 0x0F3E is RET, so it's going to read two bytes off
the stack and jump to it. This is what you're seeing at 0xF0B2 and
0xF0B3. I'd suggest you look at how RAM is addressed at the top of
memory space and see if it's correct.
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thrashbarg＠kaput.homeunix.org -
witchy＠binarydinosaurs.co.uk