CHA256B: Difference between revisions

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A [[NEO-273]] and a LS74 are used to address C ROM. The LS74 provides the 2 most significant bits. The LS139 enables one of four pairs of C ROMs using 2 address inputs depending on which 2 jumpers are connected.
These jumpers seem to apply only to those two ROMs, if the ROMs are not present, simply leave both jumpers unconnected.
 
{| class="wikitable"
|-
!C1/2 ROM type
!Jumper set
|-
|<4MiB
|J15
|-
|4MiB
|J11
|}


*Max 256Mbit C ROM (8x 32Mbit)
{| class="wikitable"
*[[NEO-273]]
|-
*[[NEO-ZMC]]
!C3/4 ROM type
*LS139,LS74
!Jumper set
|-
|<4MiB
|J16
|-
|4MiB
|J12
|}


==AES version==
{| class="wikitable"
|-
!C5/6 ROM type
!Jumper set
|-
|<4MiB
|J17
|-
|4MiB
|J13
|}


{| class="wikitable"
{| class="wikitable"
|-
|-
!C ROM type
!C7/8 ROM type
!Jumper set
!Jumper set
|-
|-
|<4MiB
|<4MiB
|J15+J16+J17+J18
|J18
|-
|-
|4MiB
|4MiB
|J11+J12+J13+J14
|J14
|}
|}
A [[NEO-273]] and a LS74 are used to address C ROM. The LS74 provides the 2 most significant bits. The LS139 enables one of four pairs of C ROMs using 2 address inputs depending on which 2 jumpers are connected.
*Max 256Mbit C ROM (8x 32Mbit)


{| class="wikitable"
{| class="wikitable"
Line 53: Line 86:
|128KiB
|128KiB
|J2+J3
|J2+J3
|}
*[[NEO-273]]
*[[NEO-ZMC]]
*LS139,LS74
==AES version==
{| class="wikitable"
|-
!C ROM type
!Jumper set
|-
|<4MiB
|J15+J16+J17+J18
|-
|4MiB
|J11+J12+J13+J14
|}
|}



Latest revision as of 20:30, 13 April 2021

COPIED VERBATIM FROM THE CHA256 ENTRY, NEEDS TO BE CHECKED

C ROMs

Up to 8 * 32Mbit ROMs (27C322) can be used for a maximum of 256Mbit. 27C800/27C160 can also be used depending on jumper configuration.

The size of largest ROM is selected using a pair of jumpers. The rest should be left unconnected.

Largest C ROM Jumper set
1MiB J5+J6
2MiB J7+J8
4MiB J9+J10

These jumpers seem to apply only to those two ROMs, if the ROMs are not present, simply leave both jumpers unconnected.

C1/2 ROM type Jumper set
<4MiB J15
4MiB J11
C3/4 ROM type Jumper set
<4MiB J16
4MiB J12
C5/6 ROM type Jumper set
<4MiB J17
4MiB J13
C7/8 ROM type Jumper set
<4MiB J18
4MiB J14

A NEO-273 and a LS74 are used to address C ROM. The LS74 provides the 2 most significant bits. The LS139 enables one of four pairs of C ROMs using 2 address inputs depending on which 2 jumpers are connected.

  • Max 256Mbit C ROM (8x 32Mbit)
M1 ROM size Jumper set
64KiB J1+J4
128KiB J2+J3

AES version

C ROM type Jumper set
<4MiB J15+J16+J17+J18
4MiB J11+J12+J13+J14
EVEN delay Jumper set
1 gate J19
2 gates J20