From ecb08b2cd6fd059ebb7cb893955c20a0995b0099 Mon Sep 17 00:00:00 2001 From: Tom <37988779+TwistedTom@users.noreply.github.com> Date: Tue, 12 Nov 2019 16:45:35 +0000 Subject: ZX Spectrum floating bus support (#5883) * floating bus * only official machine has floating bus --- src/devices/bus/spectrum/exp.h | 60 ++++++++++++++++++++++-------------------- 1 file changed, 32 insertions(+), 28 deletions(-) (limited to 'src/devices') diff --git a/src/devices/bus/spectrum/exp.h b/src/devices/bus/spectrum/exp.h index c17b88f0a9b..366e27c9e5e 100644 --- a/src/devices/bus/spectrum/exp.h +++ b/src/devices/bus/spectrum/exp.h @@ -8,34 +8,38 @@ Pinout: - A15 1 A14 - A13 2 A12 - D7 3 +5v - ¬OE 4 NC - SLOT 5 SLOT - D0 6 0v - D1 7 0v - D2 8 ¬CK - D6 9 A0 - D5 10 A1 - D3 11 A2 - D4 12 A3 - ¬INT 13 NC - ¬NMI 14 0v - ¬HALT 15 ¬OE - ¬MREQ 16 NC - ¬IORQ 17 NC - ¬RD 18 NC - ¬WR 19 ¬BUSRQ - NC 20 ¬RESET - ¬WAIT 21 A7 - +12v 22 A6 - NC 23 A5 - ¬M1 24 A4 - ¬RFSH 25 ¬ROMCS - A8 26 ¬BUSACK - A10 27 A9 - NC 28 A11 + 48K 128K/+2 +2A/+2B/+3/3B + + A B A B A B + A15 1 A14 A15 1 A14 A15 1 A14 + A13 2 A12 A13 2 A12 A13 2 A12 + D7 3 +5V D7 3 +5v D7 3 +5v + NC 4 +9V NC 4 +9V /OE ROM1 4 NC + SLOT 5 SLOT SLOT 5 SLOT SLOT 5 SLOT + D0 6 GND D0 6 GND D0 6 GND + D1 7 GND D1 7 GND D1 7 GND + D2 8 CLK D2 8 CLK D2 8 CKEXT + D6 9 A0 D6 9 A0 D6 9 A0 + D5 10 A1 D5 10 A1 D5 10 A1 + D3 11 A2 D3 11 A2 D3 11 A2 + D4 12 A3 D4 12 A3 D4 12 A3 + /INT 13 /IORQGE /INT 13 /IORQGE (+2 only) /INT 13 NC + /NMI 14 GND /NMI 14 GND /NMI 14 GND + /HALT 15 VIDEO /HALT 15 NC /HALT 15 /OE ROM2 + /MREQ 16 /Y /MREQ 16 NC /MREQ 16 /DRD + /IORQ 17 V /IORQ 17 NC /IORQ 17 /DWR + /RD 18 U /RD 18 NC /RD 18 /MTR + /WR 19 /BUSRQ /WR 19 /BUSRQ /WR 19 /BUSRQ + -5V 20 /RESET -5V 20 /RESET NC 20 /RESET + /WAIT 21 A7 /WAIT 21 A7 /WAIT 21 A7 + +12V 22 A6 +12V 22 A6 +12V 22 A6 + 12VAC 23 A5 12VAC 23 A5 -12V 23 A5 + /M1 24 A4 /M1 24 A4 /M1 24 A4 + /RFSH 25 /ROMCS /RFSH 25 /ROMCS /RFSH 25 NC + A8 26 /BUSACK A8 26 /BUSACK A8 26 /BUSACK + A10 27 A9 A10 27 A9 A10 27 A9 + NC 28 A11 NC 28 A11 RESET 28 A11 + **********************************************************************/ -- cgit v1.2.3