Analog Devices 218x.

Assembler code

ROM:0034 ; ---------------------------------------------------------------------------
ROM:0034
ROM:0034 loc_34:                                 ; CODE XREF: TIMER+CF↓j
ROM:0034                 ar = $37
ROM:0035                 dm(byte_1003F4F) = ar
ROM:0036                 jump loc_25C3
ROM:0037 ; ---------------------------------------------------------------------------
ROM:0037                 imask = $240
ROM:0038
ROM:0038 loc_38:                                 ; CODE XREF: TIMER+12↓j
ROM:0038                 ar = dm(byte_1003E33)
ROM:0039                 ar = ar - 1
ROM:003A                 if lt jump loc_38
ROM:003B                 imask = $250
ROM:003C
ROM:003C loc_3C:                                 ; CODE XREF: TIMER+16↓j
ROM:003C                 ar = dm(byte_1003E33)
ROM:003D                 ar = ar - 2
ROM:003E                 if lt jump loc_3C
ROM:003F                 imask = $269
ROM:0040
ROM:0040 loc_40:                                 ; CODE XREF: TIMER+1A↓j
ROM:0040                 ar = dm(byte_1003F12)
ROM:0041                 ar = ar + 0
ROM:0042                 if eq jump loc_40
ROM:0043                 jump loc_6E
ROM:0044 ; ---------------------------------------------------------------------------
ROM:0044
ROM:0044 loc_44:                                 ; CODE XREF: TIMER+2F↓j
ROM:0044                                         ; TIMER+38↓j ...
ROM:0044                 ena timer
ROM:0045                 ay0 = dm(byte_1002CD2)
ROM:0046                 ax0 = dm(byte_1002CD3)
ROM:0047                 ar = ay0 - ax0
ROM:0048                 if ge jump loc_4B