A while back Curt Vendel from the Atari History Museum posted a document from Atari, that had a list of chips that were being worked on. Some of them were quite common, but others are a mystery. Below is a cleaned up version of the list with some descriptions of the known chips. The initials after each description are the person who provided the information: (DLB) Dan Boris (Me) (CV) Curt Vendel (or information from his site) You can see the original document contents here.

* Part# Name Revision Date   Description (not from the original list) 6 C010444 STELLA 0444E 10/5/1983   2600 TIA (Television Interface Adaptor) (DLB) 7 C010745 6507 0745E 1/25/1983   2600 Processor (DLB) 8 C010750 6532 0750E 10/4/1983   2600 RIOT (RAM I/O Timer) (DLB) 9 C011903 PAULA 1903B 11/5/1980   2600 TIA (PAL) 10 C012294 POKEY HF2294 6/20/1983   Sound chip used in 5200, 8-bit computers, some 7800 carts, and arcades (DLB) 11 C012296 ANTIC HC2296 7/25/1983   Display DMA processor used in 8-bit computers (DLB) 12 C014328 1k RAM H4328 9/20/1982     13 C014329 FLOP. DISK CONTR. HB4329 5/11/1983     14 ** C014331 16kx1 DRAM 3-supp     15 C014377 6502 CPU HD4377 11/17/1983     16 C014795 PIA (6520) HF4795 6/2/1983   Peripherial Interface Adaptor used in 8-bit computers (DLB) 17 C014805 GTIA HC4805 2/14/1983   Main graphics chip used in 5200 and 8-bit computers (DLB) 18 C014806 SALLY HP4806 9/29/1983   Standard 6502 processor with a HALT input for stopping the processor and tri-stating the system bus. Used in the 8-bit computers. (DLB) 19 C014887 PAL ANTIC HD4887 2/24/1984   PAL version of ANTIC (DLB) 20 C014889 PAL GTIA HB4889 11/30/1983   PAL version of GTIA (DLB) 21 C015338 STAR 15338 10/31/1981     22 C015339 STELLETTE 15339D 4/7/1983     23 C015946 3870 5946A 6/8/1983     24 C016145 fast 6507 6145A 6/24/1980     25 C016150 fast 6532 6150A 6/24/1980     26 ** C016213 2716(2kx8 EPROM)     Standard 2k EPROM (DLB) 27 ** C016505 16kx4 DRAM     28 C016598 ISABEL IBEL   5/7/1981     29 C016599 STEPHANIE 6599A 6/4/1983     30 C016701 FRANTIC 6701 5/12/1981     31 C016702 BETTY 16702 1/4/1983     32 C016819 ENCODER 6819 3/31/1983     33 C016820 DECODER 6820 3/16/1983     34 C016821 Transistor Array HFEXXX 11/21/1983     35 ** C018082 16kx1 DRAM 1-supp 36 C018172 FTIA HA8172 8/24/1983     37 C018969 COMBO 8969A 6/22/1983     38 C020120 FGTIA HA0120 5/11/1984   French SECAM GTIA chip (CV) 39 C020231 SARA HC0231 5/16/1984   Custom RAM chip for 2600 cartridges (DLB) 40 C020574 PORKEY 574A 3/7/1983   stereo Pokey (CV) 41 C020577 CGIA H0577 4/4/1984   combined ANTIC & GTIA (CV) 42 ** C021463 MEG Cmos version of Pokey (CV) 43 C021697 ANTIC-E HC1697 6/19/1983   "Enhanced" ANTIC (DLB) 44 C021698 PAL ANTIC-B HC1698 6/19/1983     45 ** C021737 KERI     Antic/GTIA/Pokey combined (CV) 46 ** C021859 AMY     Sound Processor was originally a chip designed for Project "GAZA". (CV) 47 ** C024143 MERCURY     48 ** C024382 MISTY     49 ** C024421 MTV-1     50 ** C024422 RAINBOW GOLD     Sierra and/or Gaza, the high end 68000 based computer systems Atari was developing in-house prior to the sale to the Tramiels.(CV) 51 ** C024423 RAINBOW SILVER     Sierra and/or Gaza, the high end 68000 based computer systems Atari was developing in-house prior to the sale to the Tramiels.(CV) 52 ** C024424 STEPHANIE PAL     53 C024425 QUAD POKEY HA4425 6/12/1984   4 POKEY's in a single package. Used in arcades (DLB) 54 ** C024426 BENNY     55 ** C024574 MATTHEW     56 C024674 MARIA-B HD4674 6/12/1984   Main graphics chip in the 7800 (DLB) 57 ** C025307 MATT     58 C025349 MARIA-C H5349 6/6/1984   Main graphics chip in the 7800 (DLB) 59 C025632 PIC 1670 H5632 5/15/1984     60 ** C025718 PAL MARIA     PAL version of MARIA (DLB) 61 C060472 DELAY LINE 0472E 5/24/1984     62 C060609 MMU HC0609 3/9/1984     63 ** C060612 64kx1 DRAM 1-supp     64 ** C061617       65 C061618 MMU H1618 5/13/1983     66 ** C061690 6551 SIA     67 ** C061692 MODEM (N.S.)     68 ** C061693 2732A (EPROM)     Standard 4K EPROM (DLB) 69 ** C061720 SPEECH SYN     70 ** C061842 MMU     71 C061917 PAL C H1917 8/5/1983     72 C061918 PAL B H1918 8/3/1983     73 C061919 PAL A HB1919 3/14/1984     74 ** C061921 DISK CONTROLLER     75 C061922 FREDDIE HA1922 3/21/1984   DRAM control chip, used in the 1450 8-bit computer (DLB) 76 ** C061928 8050 CPU 77 C061991 FREDDIE (ASG) H1991 12/12/1983     78 ** C062016 MODEM (T.I.)     79 ** C062208 280A     This may have been Z80A (DLB) 80 ** C062209 6116 (2kx8 SRAM)     Standard 2K SRAM 81 ** C062210 6845 VIP CONTR.     82 ** C062211 280 PERIF. INTERFACE     83 ** C137410 ICY     * = The asterisks in this column where pefixed to the part numbers. Not sure what they indicate.