diff --git a/EIPS/eip-1985.md b/EIPS/eip-1985.md
index a2787c62..dd6417eb 100644
--- a/EIPS/eip-1985.md
+++ b/EIPS/eip-1985.md
@@ -50,14 +50,15 @@ They restrict the results (i.e. values pushed to the stack) of the instructions
- `CREATE` (`0xf0`),
- `CREATE2` (`0xf5`).
-4. *buffer size*
+4. *buffer size*, *code size*, *memory size*
is a range between `0` and `0xffffffff` (`2**32 - 1`, `4294967295`).
It affects the following instructions:
- `CALLDATASIZE` (`0x36`),
- `CODESIZE` (`0x38`),
- `EXTCODESIZE` (`0x3b`),
- `RETURNDATASIZE` (`0x3d`),
- - `MSIZE` (`0x59`).
+ - `MSIZE` (`0x59`),
+ - `PC` (`0x58`).
## Rationale
@@ -85,10 +86,24 @@ IEEE Std 1003.1-2001 (POSIX.1) leaves that definition implementation defined.
The size of addresses is specified in the [Yellow Paper] as 20 bytes.
E.g. the `COINBASE` instruction is specified to return *H*c ∈ 𝔹20 which has 20 bytes.
+### Memory size
+
+Memory expansion cost is not linear and is determined by the following formula:
+ cost = cost_per_word * number_of_words + (number_of_words ^ 2 / 512)
+
+Expanding to over `2^32 - 1` bytes would cost `35184774742016` gas. This number fits into the gas limit imposed above (`2 ^ 63 - 1`) and would cost around 35184 Ether in a transaction to exhaust, with a 1 GWei gas cost, which can be attained on mainnet.
+
+However, setting the limit `2^32 - 1` is beneficial from a VM design perspective and we believe limiting memory should be done via carefully selecting the block gas limit.
+
+### Code size
+
+[EIP-170](http://eips.ethereum.org/EIPS/eip-170) has implemented a code size limit of 0x6000, however even before that, it was practically impossible to deploy a code blob exceeding `2**32 - 1` bytes in size.
+
### Comparing current implementations
- Timestamp is implemented as a 64-bit value in [Aleth], [geth] and [Parity]
- Block gas limit is implemented as a 64-bit in [Aleth] and [geth]
+- Memory, buffer and code sizes are implemented as 64-bit values in [geth]
## Backwards Compatibility
@@ -104,7 +119,8 @@ TBA
## References
-[EIP-106](https://github.com/ethereum/EIPs/issues/106) proposed the block gas limit to be limited at `2**63 - 1`.
+- [EIP-92](https://github.com/ethereum/EIPs/issues/92) proposed the transaction gas limit to be limited at `2**63 - 1` and had a lengthy discussion about other limits.
+- [EIP-106](https://github.com/ethereum/EIPs/issues/106) proposed the block gas limit to be limited at `2**63 - 1`.
## TODO