C128 external function ROM problem

[C128DCR]

Hello.
I built a 8×32=256 KB internal function ROM (U36) EPROM.
Servant, Keydos, Superchip, Super 81 utilities, BASIC 8, TASS (turbo assembler), GEOS128 V2 1571, GEOS128 V2 1581.
All ROM OK with 3 switches. I use C128DCR.
I modified a C64 EPROM card to external function ROM.
I installed a other 256 KB EPROM into card with 8 ROMs, but 5 ROMs not work, not start (I remove internal U36 EPROM).
3 OK, Servant, Keydos, BASIC 8.

Why do the 5 ROMs not work?
Internal and external function ROM banks, page 10-11: http://www.cubic.org/~doj/c64/mapping128.pdf

[eslapion]

Got a schematic of what you did ?

[C128DCR]

Simple. I connect the expansion port ROMH and ROML to 74LS08 AND gate pin 12-13, I connect the output (pin 11) to 29020 flash ROM pin 24 OE, output enable (= 27256 EPROM pin 22). This = U36 internal function ROM.
C128 schematics: http://www.zimmers.net/anonftp/pub/cbm/ ... 4-left.gif
http://www.zimmers.net/anonftp/pub/cbm/ ... -right.gif
29C020: http://home.onego.ru/~sprut/Schemes/PRO ... 29c020.gif
74LS08: http://www.csus.edu/indiv/p/pangj/class ... g/7408.gif

I use C128 inbuilt monitorprogram, $B8000-$BCFFF, $BE000-$BFFFF OK, 32 KB $B8000-BFFFF external function ROM OK at all 8 ROMs. Bank 11.
At $D000-DFFF not bank command (always I/O, or RAM), but this 4 KB OK, because Servant and keydos all function OK.
Internal and external function ROM banks, page 10-11: http://www.cubic.org/~doj/c64/mapping128.pdf
Internal U36 ROM = bank 7.

[eslapion]

I have to bow and admit this is beyond me.

AFAIK, ROML and ROMH can each signal an access to an area of 8KBytes at the most. Of you combine the 2 with a 74LS08 then this create an accessible area of 16K. Function ROMs for the C128 are supposed to be 32K.

[C128DCR]

Noooo. C128 expansion port pinouts.
C64, and C128 C64 mode.
C128 and C64 mode not same. In C64 mode ROML and ROMH = 8 KB, look Exrom+Game line.
In C128 mode Exrom and Game line unused.
Making a C64 Cartridge.
Making a C128 cartridge.
74LS08 OK, look C64 schematics: 250469 left side. 250469 right side.
251715 BASIC and KERNAL line connected into U3 74LS08 pin 12+13, and pin 11 connected into BASIC+KERNAL ROM pin 22.
Here 2×8 KB=16 KB. In C128 mode 2×16 KB=32 KB.

[Mac Bacon]

If three programs work and five programs do not, then my best guess is that those five programs simply are not prepared to run from bank 8 (external function rom). Check their init codes with the monitor; maybe they switch to bank 4 because they expect to be run from there.