FW: 8085 Address Decoding

[Adrian Graham]

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?

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